As filed with the Securities and Exchange Commission on July 18, 2001
                                                      Registration No. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                ---------------

                                    FORM S-3
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                                ---------------

                                  ONEOK, INC.
             (Exact Name of Registrant as Specified in Its Charter)

                Oklahoma                               73-1520922
    (State or Other Jurisdiction of                 (I.R.S. Employer
     Incorporation or Organization)              Identification Number)

                             100 West Fifth Street
                             Tulsa, Oklahoma 74103
                                 (918) 588-7000
    (Address, Including Zip Code, and Telephone Number, Including Area Code,
                  of Registrant's Principal Executive Offices)

                                   Jim Kneale
          Senior Vice President, Treasurer and Chief Financial Officer
                                  ONEOK, Inc.
                             100 West Fifth Street
                             Tulsa, Oklahoma 74103
                                 (918) 588-7000
           (Name, Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent For Service)

                                   Copies to:

             John R. Barker                         Robert A. Yolles
            Gable & Gotwals                    Jones, Day, Reavis & Pogue
   100 West Fifth Street, Suite 1100                 77 West Wacker
         Tulsa, Oklahoma 74103                  Chicago, Illinois 60601
             (918) 595-4800                          (312) 782-3939

                                ---------------

        Approximate date of commencement of proposed sale to the public:
  From time to time after the effective date of this Registration Statement as
               determined by market conditions and other factors.

                                ---------------

  If the only securities being registered on this form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. [_]

  If any of the securities being registered on this form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or
interest reinvestment plans, check the following box. [X]

  If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following
box and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. [_]

  If this form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [_]

  If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [_]

                                ---------------

  The Registrant hereby amends this Registration Statement on such date or
dates as may be necessary to delay its effective date until the Registrant
shall file a further amendment which specifically states that this Registration
Statement shall thereafter become effective in accordance with Section 8(a) of
the Securities Act of 1933 or until this Registration Statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a),
may determine.

                        CALCULATION OF REGISTRATION FEE

--------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------

                                                      Proposed Maximum
              Title of Each Class                        Aggregate                  Amount of
         of Securities to Be Registered             Offering Price(1)(2)       Registration Fee(3)
--------------------------------------------------------------------------------------------------
                                                                      
Debt Securities and Common Stock, par value
 $0.01 per share (including preferred share
 purchase rights)...............................        $500,000,000                 $125,000
--------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------

(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rule 457(o) under the Securities Act. In no event will the
    aggregate initial offering price of all Debt Securities and Common Stock
    issued from time to time pursuant to this Registration Statement exceed
    $500,000,000. If any Debt Securities are issued at an original issue
    discount, then the offering price will be deemed to be the principal amount
    that results in an aggregate initial offering price of up to $500,000,000,
    less the dollar amount of any Debt Securities or Common Stock previously
    issued hereunder.
(2) Exclusive of accrued interest, if any.
(3) An aggregate of $60,000,000 of Debt Securities and Common Stock are being
    carried forward from Registration Statement No. 333-36928. In connection
    with Registration Statement No. 333-36928, registration fees of $15,840
    attributable to that $60,000,000 of Debt Securities and Common Stock were
    previously paid and are credited against the registration fees payable in
    connection with this Registration Statement.

                                ---------------

  Pursuant to Rule 429 under the Securities Act of 1933, this Registration
Statement contains a combined prospectus that also relates to $60,000,000 of
Debt Securities and Common Stock registered under a registration statement on
Form S-3 (File No. 333-36928), which was declared effective on June 19, 2000,
which securities have not been offered or sold as of the date of the filing of
this Registration Statement (the "Previously Registered Securities"). This
Registration Statement constitutes Post-Effective Amendment No. 1 to
Registration Statement No. 333-36928, pursuant to which the total amount of
unsold Previously Registered Securities registered on Registration Statement
No. 333-36928, without limitation as to class of securities, may be offered and
sold as Debt Securities and Common Stock. In the event that any of such
Previously Registered Securities are offered and sold prior to the effective
date of this Registration Statement, the amount of such Previously Registered
Securities so sold will not be included in the Prospectus hereunder.

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--------------------------------------------------------------------------------


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+The information in this prospectus is not completed and may be changed. We    +
+may not consummate the exchange offer until the registration statement filed  +
+with the Securities and Exchange Commission is effective. This prospectus is  +
+not an offer to sell these notes and is not soliciting an offer to buy these  +
+notes in any state where the offer or sale is not permitted.                  +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
       Subject to completion, Preliminary Prospectus dated July 18, 2001

                                  ONEOK, Inc.

                                  $500,000,000

                                Debt Securities

                                  Common Stock

                                  -----------

  We may offer from time to time in one or more issuances, (1) one or more
series of unsecured Debt Securities, which may be senior notes or debentures or
other unsecured evidences of indebtedness, or (2) shares of our Common Stock.
The Debt Securities and the Common Stock are collectively referred to in this
prospectus as the "Securities." The aggregate initial offering price of the
Securities that are offered will not exceed $500,000,000. We will offer the
Securities in an amount and on terms to be determined by market conditions at
the time of the offering.

  We will provide you with the specific terms of the particular Securities
being offered in supplements to this prospectus. You should read this
prospectus and each related supplement carefully before you invest. This
prospectus may not be used to sell Securities unless accompanied by a
prospectus supplement.

                                  -----------

  Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or passed upon the
adequacy or accuracy of this prospectus. Any representation to the contrary is
a criminal offense.

                                  -----------

                  The date of this Prospectus is      , 2001.


                               TABLE OF CONTENTS


                                                                          
About This Prospectus.......................................................   2
Where You Can Find More Information.........................................   2
Forward-Looking Information.................................................   3
About ONEOK.................................................................   4
Use Of Proceeds.............................................................   4
Ratio Of Earnings To Fixed Charges..........................................   5
Description Of Debt Securities..............................................   5
Description Of Capital Stock................................................  13
Plan Of Distribution........................................................  25
Legal Matters...............................................................  26
Experts.....................................................................  26


                             ABOUT THIS PROSPECTUS

   This prospectus is part of a registration statement that ONEOK ("we" or
"ONEOK") filed with the Securities and Exchange Commission using a "shelf"
registration process. Using this process, we may offer the Securities described
in this prospectus in one or more offerings with a total initial offering price
of up to $500,000,000. This prospectus provides you with a general description
of the Securities we may offer. Each time we offer Securities, we will provide
you a prospectus supplement and any pricing supplement that will contain
information about the specific terms of that particular offering. The
prospectus supplement or pricing supplement may also add, update or change
information contained in this prospectus. To obtain additional information that
may be important to you, you should read the exhibits filed by us with the
registration statement of which this prospectus is a part or our other filings
with the Securities and Exchange Commission. You also should read this
prospectus and any prospectus supplement or pricing supplement together with
the additional information described under the heading "Where You Can Find More
Information."

                      WHERE YOU CAN FIND MORE INFORMATION

   We file annual, quarterly and special reports, proxy statements and other
information with the Securities and Exchange Commission. You can read and copy
any materials we file with the Securities and Exchange Commission at its Public
Reference Room at 450 Fifth Street, N.W., Washington, D.C. 20549 and at its
regional offices located at Seven World Trade Center, New York, New York 10048
and at 500 West Madison Street, Chicago, Illinois 60661. You can obtain
information about the operations of the Securities and Exchange Commission
Public Reference Room by calling the Securities and Exchange Commission at 1-
800-SEC-0330. The Securities and Exchange Commission also maintains a Web site
that contains information we file electronically with the Securities and
Exchange Commission, which you can access over the Internet at
http://www.sec.gov. Our Common Stock is listed on the New York Stock Exchange
(NYSE: OKE), and you can obtain information about us at the offices of the New
York Stock Exchange, 20 Broad Street, New York, New York 10005.

   This prospectus is part of a registration statement we have filed with the
Securities and Exchange Commission relating to the Securities. As permitted by
Securities and Exchange Commission rules, this prospectus does not contain all
of the information we have included in the registration statement and the
accompanying exhibits we file with the Securities and Exchange Commission. You
may refer to the registration statement and the exhibits for more information
about us and the Securities. The registration statement and the exhibits are
available at the Securities and Exchange Commission's Public Reference Room or
through its Web site.

                                       2


   The Securities and Exchange Commission allows us to "incorporate by
reference" the information we file with it, which means that we can disclose
important information to you by referring you to those documents. The
information we incorporate by reference is an important part of this
prospectus, and later information that we file with the Securities and Exchange
Commission will automatically update and supersede some of this information. We
incorporate by reference the documents listed below, and any future filings we
make with the Securities and Exchange Commission under Section 13(a), 13(c), 14
or 15(d) of the Securities Exchange Act of 1934 until we sell all the
Securities. The documents we incorporate by reference are:

  . our annual report on Form 10-K for the year ended December 31, 2000;

  . our report on Form 10-Q for the quarterly period ended March 31, 2001;

  . our current reports on Form 8-K dated January 19, 2001, January 29, 2001,
    February 22, 2001, May 23, 2001, May 25, 2001, May 30, 2001 and June 26,
    2001;

  . the description of our Common Stock contained in our Form 8-A
    registration statement filed with the Securities and Exchange Commission
    on November 21, 1997, including any amendment or report filed for the
    purpose of updating that description; and

  . the description of our preferred share purchase rights contained in our
    Form 8-A registration statement filed with the Securities and Exchange
    Commission on November 28, 1997, including any amendment or report filed
    for the purpose of updating that description.

   You may request a copy of these filings (other than an exhibit to the
filings unless we have specifically incorporated that exhibit by reference into
the filing), at no cost, by writing or telephoning us at the following address:

                                  ONEOK, Inc.
                             100 West Fifth Street
                             Tulsa, Oklahoma 74103
                       Attention: Chief Financial Officer
                           Telephone: (918) 588-7000

   You should rely only on the information incorporated by reference or
provided in this prospectus or any prospectus supplement. We have not
authorized anyone else to provide you with different information. We may only
use this prospectus to sell Securities if it is accompanied by a prospectus
supplement. We are only offering the Securities in states where the offer is
permitted. You should not assume that the information in this prospectus, the
applicable prospectus supplement or any applicable pricing supplement is
accurate as of any date other than the date on the front of those documents.

                          FORWARD-LOOKING INFORMATION

   Some of the statements contained and incorporated in this prospectus are
forward-looking statements within the meaning of the Private Securities
Litigation Reform Act of 1995. The forward-looking statements relate to
anticipated financial performance, management's plans and objectives for future
operations, business prospects, outcome of regulatory proceedings, market
conditions and other matters. The Private Securities Litigation Reform Act of
1995 provides a safe harbor for forward-looking statements in various
circumstances. The following discussion is intended to identify important
factors that could cause future outcomes to differ materially from those set
forth in the forward-looking statements.

   Forward-looking statements include the items identified in the preceding
paragraph, the information concerning possible or assumed future results of
operations and other statements contained or incorporated in this prospectus
identified by words such as "anticipate," "estimate," "expect," "intend,"
"believe," "projection" or "goal."

                                       3


   You should not place undue reliance on the forward-looking statements. They
are based on known and unknown risks, uncertainties and other factors that may
cause our actual results, performance or achievements to be materially
different from any future results, performance or achievements expressed or
implied by the forward-looking statements. Those factors may affect our
operations, markets, products, services and prices. In addition to any
assumptions and other factors referred to specifically in connection with the
forward-looking statements, factors that could cause our actual results to
differ materially from those contemplated in any forward-looking statement
include, among others, the following:

  . the effects of weather and other natural phenomena on sales and prices;

  . increased competition from other energy suppliers as well as alternative
    forms of energy;

  . the capital intensive nature of our business;

  . further deregulation, or "unbundling," of the natural gas business;

  . competitive changes in the natural gas gathering, transportation and
    storage business resulting from deregulation, or "unbundling," of the
    natural gas business;

  . the profitability of assets or businesses acquired by us;

  . risks of hedging, marketing and trading activities as a result of changes
    in energy prices;

  . economic climate and growth in the geographic areas in which we do
    business;

  . the uncertainty of gas and oil reserve estimates;

  . the timing and extent of changes in commodity prices for natural gas,
    electricity, crude oil and natural gas liquids;

  . the effects of changes in governmental policies and regulatory actions,
    including income taxes, environmental compliance and authorized rates;

  . the results of litigation relating to our previously proposed acquisition
    of Southwest Gas Corporation or to the termination of our merger
    agreement with Southwest Gas; and

  . the other factors listed in the reports we have filed and may file with
    the Securities and Exchange Commission, which are incorporated by
    reference.

   Other factors and assumptions not identified above were also involved in the
making of the forward-looking statements. The failure of those assumptions to
be realized, as well as other factors, may also cause actual results to differ
materially from those projected. We have no obligation and make no undertaking
to update publicly or revise any forward-looking statements.

                                  ABOUT ONEOK

   ONEOK and its subsidiaries engage in several aspects of the energy business.
We purchase, gather, process, transport, store and distribute natural gas. We
drill for and produce gas and oil, and extract, sell and market natural gas
liquids. We also engage in the natural gas marketing and trading business and
in the production and marketing of electricity. Our regulated natural gas
utility businesses distribute natural gas to approximately 1.4 million
customers in the states of Oklahoma and Kansas.

                                USE OF PROCEEDS

   Unless we inform you otherwise in the prospectus supplement, we will use the
net proceeds from the sale of the Securities offered by this prospectus for
general corporate purposes. These purposes may include repayment and
refinancing of debt, acquisitions, working capital, capital expenditures and
repurchases and redemptions of securities. Pending any specific application, we
may initially invest funds in short-term marketable securities or apply them to
the reduction of short-term indebtedness.


                                       4


                       RATIO OF EARNINGS TO FIXED CHARGES

   Our ratio of earnings to fixed charges for each of the periods shown is as
follows:



                                                                         For the years ended August
                                                                                     31,
For the three months ended  For the year ended For the four months ended ---------------------------
      March 31, 2001        December 31, 2000      December 31, 1999      1999   1998   1997   1996
--------------------------  ------------------ ------------------------- ------ ------ ------ ------
                                                                            

           3.66 x                 2.88 x                2.98 x           4.06 x 5.50 x 3.51 x 3.28 x


   We have computed the ratios of earnings to fixed charges by dividing
earnings by fixed charges. For this purpose, "earnings" consists of income
before cumulative effect of a change in accounting principle plus fixed charges
and income taxes, less undistributed income from equity investees. "Fixed
charges" consists of interest charges, the representative interest portion of
operating leases and the amortization of debt discounts and issue costs.

                         DESCRIPTION OF DEBT SECURITIES

   The following description states the general terms and provisions of our
unsecured Debt Securities. In this prospectus, "Debt Securities" means the
debentures, notes, bonds and other evidences of indebtedness that we will issue
under an Indenture that we entered into with The Chase Manhattan Bank, formerly
known as Chase Bank of Texas, National Association, as trustee, on September
24, 1998. Each prospectus supplement that we provide when we offer Debt
Securities will describe the specific terms of the Debt Securities offered
through that prospectus supplement and any general terms outlined in this
section that will not apply to those Debt Securities.

   We have summarized the material terms and provisions of the Indenture in
this section. The summary is not complete. We have filed the form of the
Indenture as an exhibit to the registration statement of which this prospectus
forms a part. You should read the form of Indenture for additional information
before you buy any Debt Securities. The Indenture is qualified under the Trust
Indenture Act of 1939. You should refer to the Trust Indenture Act of 1939 for
provisions that apply to the Debt Securities. This summary also is subject to
and qualified by reference to the description of the particular terms of the
Debt Securities described in the applicable prospectus supplement or
supplements and pricing supplement or supplements. Capitalized terms used but
not defined in this summary have the meanings specified in the Indenture.

   The Debt Securities will be our unsecured obligations and will rank equally
with any of our other senior, unsecured debt. Debt Securities issued under the
Indenture will be issued as part of a series that has been established pursuant
to a supplemental indenture or other corporate action designating the specific
terms of the series of Debt Securities. A prospectus supplement will describe
these terms and will include, among other things, the following:

  . the title of the Debt Securities of the particular series;

  . the total principal amount of those Debt Securities and the percentage of
    their principal amount at which we will issue those Debt Securities;

  . the date or dates on which the principal of those Debt Securities will be
    payable;

  . the interest rate, the method for determining the interest rate (if the
    interest rate is variable), the date from which interest will accrue,
    interest payment dates and record dates for interest payments;

  . the place or places where payments on those Debt Securities will be made,
    where holders may surrender their Debt Securities for transfer or
    exchange and where to serve notices or demands;

  . any provisions for optional redemption or early repayment;

  . any provisions that would obligate us to redeem, purchase or repay those
    Debt Securities;

  . whether payments on the Debt Securities of the particular series will be
    payable by reference to any index, formula or other method;

                                       5


  . any deletions from, changes of or additions to the events of default or
    covenants described in this prospectus;

  . the portion of the principal amount of those Debt Securities that will be
    payable if the maturity is accelerated, if other than the entire
    principal amount;

  . any additional means of defeasance of all or any portion of those Debt
    Securities, any additional conditions or limitations to defeasance of
    those Debt Securities or any changes to those conditions or limitations;

  . any provisions granting special rights to holders of the Debt Securities
    of the particular series upon the occurrence of events identified in the
    prospectus supplement;

  . if other than the trustee, the designation of any paying agent or
    security registrar for those Debt Securities; and the designation of any
    transfer or other agents or depositories for those Debt Securities;

  . whether we will issue the Debt Securities of the particular series in
    individual certificates to each holder or in the form of temporary or
    permanent global securities that a depository will hold on behalf of
    holders;

  . the denominations in which we will issue the Debt Securities of the
    particular series or in which they may be owned, if other than $1,000 or
    any integral multiple of $1,000;

  . whether and in what circumstances any additional amounts may be payable
    on those Debt Securities to foreign holders; and

  . any other terms or conditions that are consistent with the Indenture.

   We may sell the Debt Securities at a discount (which may be substantial)
below their stated principal amount. These discounted Debt Securities may bear
no interest or interest at a rate that at the time of issuance is below market
rates. We will describe in the prospectus supplement any material United States
federal income tax consequences and other special considerations.

Restrictive Covenants

   We have agreed to two principal restrictions on our activities for the
benefit of holders of the Debt Securities. The restrictive covenants summarized
below will apply to a series of Debt Securities (unless waived or amended) as
long as any of those Debt Securities are outstanding, unless the prospectus
supplement for the series states otherwise. We have used in this summary
description capitalized terms that we have defined below under "--Glossary." In
this description of the covenants only, all references to "us" or "we" mean
ONEOK and our principal subsidiaries, unless the context clearly indicates
otherwise. Our principal subsidiaries are those that own or lease a Principal
Property.

   Other than the restrictions on Liens and Sale/Leaseback transactions
described below, the Indenture and the Debt Securities do not contain any
covenants or other provisions designed to protect holders of any Debt
Securities in the event we participate in a highly leveraged transaction. The
Indenture and the Debt Securities also do not contain provisions that give
holders of the Debt Securities the right to require us to repurchase their
securities in the event of change-in-control, recapitalization or similar
restructuring or otherwise or upon a decline in our credit rating.

   For these purposes, "debt" includes all notes, bonds, debentures or similar
evidences of obligations for borrowed money.

 Limitation on Liens

   We have agreed that we will issue, assume or guarantee debt for borrowed
money secured by any Lien upon a Principal Property or shares of stock or debt
of any principal subsidiary only if we secure the Debt Securities equally and
ratably with or prior to the debt secured by that Lien. If we secure the Debt
Securities in

                                       6


this manner, we have the option to secure any of our other debt or obligations
equally and ratably with or prior to the debt secured by the Lien and,
accordingly, equally and ratably with the Debt Securities. This covenant has
exceptions that permit:

  . Liens that existed on September 29, 1998, the date we first issued a
    series of Debt Securities;

  . Liens on any Principal Property or shares of stock or debt of any entity
    that constitutes a principal subsidiary existing at the time we merge or
    consolidate with that entity or acquire its property or at the time the
    entity becomes a principal subsidiary;

  . Liens on any Principal Property existing at the time we acquire that
    Principal Property so long as the Lien does not extend to any of our
    other Principal Property;

  . Liens on any Principal Property, and any Lien on the shares of stock of
    any principal subsidiary formed for the purpose of acquiring that
    Principal Property, either:

    . securing all or part of the cost of acquiring, constructing,
      improving, developing or expanding the Principal Property that was
      incurred before, at or within 12 months after the latest of the
      acquisition or completion of the assets or their commencing
      commercial operation; or

    . securing debt to finance the purchase price of the Principal Property
      or the cost of constructing, improving, developing or expanding the
      assets that was incurred before, at or within 12 months after the
      latest of the acquisition or completion of the assets or their
      commencing commercial operation;

  . Liens on any Principal Property or shares of stock or debt of any
    principal subsidiary to secure debt owed to us;

  . Liens securing industrial development, pollution control or other revenue
    bonds of a government entity;

  . Liens arising in connection with a project financed with, and securing,
    Non-Recourse Indebtedness;

  . statutory or other Liens arising in the ordinary course of business and
    relating to amounts that are not delinquent or remain payable without
    penalty or that we are contesting in good faith;

  . Liens (other than Liens imposed by the Employee Retirement Income
    Security Act of 1974) on our property incurred or required in connection
    with workmen's compensation, unemployment insurance and other social
    security legislation;

  . Liens securing taxes that remain payable without penalty or that we are
    contesting in good faith if we believe we have adequate reserves for the
    taxes in question;

  . rights that any governmental entity may have to purchase or order the
    sale of any of our property upon payment of reasonable compensation;

  . rights that any governmental entity may have to terminate any of our
    franchises, licenses or other rights or to regulate our property and
    business;

  . Liens that we do not assume or on which we do not customarily pay
    interest and that exist on real estate or other rights we acquire for
    sub-station, measuring station, regulating station, gas purification
    station, compressor station, transmission line, distribution line or
    right-of-way purposes;

  . easements or reservations in our property for roads, pipelines, gas
    transmission and distribution lines, electric light and power
    transmission and distribution lines, water mains and other similar
    purposes and zoning ordinances, regulations and restrictions that do not
    impair the use of the property in the operation of our business; and

  . any extensions, renewals, substitutions or replacements of the above-
    described Liens or any debt secured by these Liens if both:

    . the amount of debt secured by the new Lien and not otherwise
      permitted does not exceed the principal amount of debt so secured at
      the time of the renewal or refunding; and

    . the new Lien is limited to the property (plus any improvements)
      secured by the original Lien.

                                       7


   In addition, without securing the Debt Securities as described above, we may
issue, assume or guarantee debt that the Lien covenant would otherwise restrict
in a total principal amount that, when added to all of our other outstanding
debt that the Lien covenant would otherwise restrict and the total amount of
Attributable Debt outstanding for Sale/Leaseback Transactions, does not exceed
a "basket" equal to 15% of Consolidated Net Tangible Assets. When calculating
this total principal amount, we exclude from the calculation Attributable Debt
from Sale/Leaseback Transactions in connection with which we have purchased
property or retired debt as described below under "--Limitation on
Sale/Leaseback Transactions."

 Limitation on Sale/Leaseback Transactions

   We have agreed that we will enter into a Sale/Leaseback Transaction only if
at least one of the following applies:

  . we could incur debt secured by a Lien on the Principal Property that is
    the subject of that Sale/Leaseback Transaction;

  . the Attributable Debt subject to that Sale/Leaseback Transaction would be
    in an amount permitted under the "basket" described above under "--
    Limitation on Liens";

  . the proceeds of that Sale/Leaseback Transaction are used for our business
    and operations; or

  . within the period ending 12 months after the closing of the
    Sale/Leaseback Transaction, we apply the net proceeds of the
    Sale/Leaseback Transaction to the voluntary retirement of any Debt
    Securities issued under the Indenture or Funded Indebtedness (other than
    Funded Indebtedness that we hold or that is subordinate in right of
    payment to any Debt Securities issued under the Indenture).

 Glossary

   "Attributable Debt" means, as to any particular lease under which any Person
is at the time liable, at any date as of which the amount thereof is to be
determined, the total net amount of rent required to be paid by that Person
under the lease during the remaining term thereof (excluding amounts required
to be paid on account of maintenance and repairs, services, insurance, taxes,
assessments, water rates and similar charges and contingent rents), discounted
from the respective due dates thereof at the weighted average of the rates of
interest (or yield to maturity, in the case of Debt Securities originally sold
at a discount) borne by the Debt Securities then outstanding under the
Indenture, compounded annually.

   "Consolidated Net Tangible Assets" means (1) the total amount of assets
(less applicable reserves and other properly deductible items) that under
generally accepted accounting principles, or GAAP, would be included on a
consolidated balance sheet of ours and our subsidiaries after deducting
therefrom (A) all current liabilities, provided, however, that there will not
be deducted billings recorded as revenues deferred pending the outcome of rate
proceedings (less applicable income taxes thereon), if and to the extent the
obligation to refund the same has not been finally determined, (B) appropriate
allowance for minority interests in common stocks of subsidiaries and (C) all
goodwill, trade names, trademarks, patents, unamortized debt discount and
expense and other like intangibles, which in each case under GAAP would be
included on the consolidated balance sheet, less (2) the amount which would be
so included on the consolidated balance sheet for investments (less applicable
reserves) made in subsidiaries.

   "Funded Indebtedness" as applied to any Person, means all debt of that
Person maturing after, or renewable or extendible at that Person's option
beyond, 12 months from the date of determination.

   "Lien" means any lien, mortgage, pledge, encumbrance, charge or security
interest securing debt; provided, however, that the following types of
transactions will not be considered for purposes of this definition to result
in a Lien: (1) any acquisition by us of any property or assets subject to any
reservation or exception under the terms of which any vendor, lessor or
assignor creates, reserves or excepts or has created, reserved or excepted an
interest in oil, gas or any other mineral in place or the proceeds thereof, (2)
any conveyance or assignment

                                       8


whereby we convey or assign to any Person or Persons an interest in oil, gas or
any other mineral in place or the proceeds thereof, (3) any Lien upon any
property or assets either owned or leased by us or in which we own an interest
that secures for the benefit of the Person or Persons paying the expenses of
developing or conducting operations for the recovery, storage, transportation
or sale of the mineral resources of the property or assets (or property or
assets with which it is unitized) the payment to that Person or Persons of our
proportionate part of the development or operating expenses or (4) any hedging
arrangements entered into in the ordinary course of business, including any
obligation to deliver any mineral, commodity or asset in connection with the
arrangement.

   "Non-Recourse Indebtedness" means, at any time, debt incurred after the date
of the Indenture by us in connection with the acquisition of property or assets
by us or the financing of the construction of or improvements on property,
whenever acquired, provided that, under the terms of that debt and pursuant to
applicable law, the recourse at that time and thereafter of the lenders with
respect to the debt is limited to the property or assets so acquired, or the
construction or improvements, including debt as to which a performance or
completion guarantee or similar undertaking was initially applicable to the
debt or the related property or assets if the guarantee or similar undertaking
has been satisfied and is no longer in effect.

   "Person" means any individual, corporation, partnership, limited liability
company, joint venture, association, joint-stock company, trust, unincorporated
organization or government or any agency or political subdivision thereof.

   "Principal Property" means any property located in the United States, except
any property that in the opinion of our board of directors is not of material
importance to the total business conducted by us and our consolidated
subsidiaries.

   "Sale/Leaseback Transaction" means any arrangement with any Person pursuant
to which we lease any Principal Property that has been or is to be sold or
transferred by us to that Person, other than (1) a lease for a term, including
renewals at the option of the lessee, of not more than three years or
classified as an operating lease under GAAP, (2) leases between us and one of
our principal subsidiaries or between principal subsidiaries, (3) leases of a
Principal Property executed by the time of, or within 12 months after the
latest of, the acquisition, the completion of construction or improvement, or
the commencement of commercial operation, of the Principal Property and (4) the
ground lease for ONEOK Plaza, 100 West Fifth Street, Tulsa, Oklahoma 74103.

Consolidation, Merger and Sale of Assets

   The Indenture generally permits a consolidation or merger between us and
another entity. It also permits the sale by us of all or substantially all of
our assets. We have agreed, however, that we will consolidate with or merge
into any entity or transfer or dispose of all or substantially all of our
assets to any entity only if:

  . immediately after giving effect to the transaction, no default or event
    of default under the Indenture would have occurred and be continuing or
    would result from the transaction;

  . we are the continuing corporation or, if we are not the continuing
    corporation, the resulting entity is organized and existing under the
    laws of any United States jurisdiction and assumes the due and punctual
    payments on the Debt Securities and the performance of our covenants and
    obligations under the Indenture and those Debt Securities; and

  . we provide the trustee with a certificate and a legal opinion, each
    stating that the Indenture permits the transaction.

   If we engage in any of these transactions that result in any Principal
Property or shares of stock or debt of any principal subsidiary becoming
subject to any Lien and unless we are otherwise able to create that Lien, the
Indenture provides that the Debt Securities (so long as those Debt Securities
are entitled to the protection of the "Limitation on Liens" covenant) will be
secured to at least the same extent as the debt that would become secured by
the Lien as a result of the transaction.

                                       9


Events of Default

   Unless we inform you otherwise in the prospectus supplement, the following
are events of default for a series of Debt Securities:

  . our failure to pay interest on that series of Debt Securities for 30 days
    after it becomes due and payable;

  . our failure to pay principal of or any premium on that series of Debt
    Securities when due;

  . our failure to comply with any of our covenants or agreements for that
    series of Debt Securities or in the Indenture (other than an agreement or
    covenant that we have included in the Indenture solely for the benefit of
    less than all series of Debt Securities) for 60 days after the trustee or
    the holders of at least 25% in principal amount of all outstanding Debt
    Securities affected by that failure provide written notice to us;

  . the default under any agreement under which we or any subsidiary that
    owns or leases Principal Property have at the time outstanding debt in
    excess of $15,000,000 and, if that debt has not already matured, it has
    been accelerated and the acceleration is not rescinded within 30 days
    after we receive notice from the trustee or the holders of at least 25%
    in principal amount of all outstanding Debt Securities of a series so
    long as, prior to the entry of judgment in favor of the trustee for
    payment of the Debt Securities of that series, we do not cure the
    default, or the default under the agreement has not been waived;

  . various events involving our bankruptcy, insolvency or reorganization; or

  . any other event of default provided for that series of Debt Securities.

   A default under one series of Debt Securities will not necessarily be a
default under another series. The trustee may withhold notice to the holders of
a series of Debt Securities of any default or event of default (except in any
payment on that series of Debt Securities) if the trustee considers it in the
interest of the holders of that series of Debt Securities to do so.

   If an event of default for any series of Debt Securities occurs and is
continuing, the trustee or the holders of at least 25% in principal amount of
the outstanding Debt Securities of the series affected by the default (or, in
some cases, 25% in principal amount of all Debt Securities affected, voting as
one class) may require us to pay on an accelerated basis the principal of and
all accrued and unpaid interest on those Debt Securities. The holders of a
majority in principal amount of the outstanding Debt Securities of the series
affected by the default (or of all Debt Securities affected, voting as one
class) may in some cases rescind this accelerated payment requirement.

   If an event of default occurs and is continuing, the trustee must use the
degree of care and skill of a prudent man in the conduct of his own affairs.
The trustee will become obligated to exercise any of its powers under the
Indenture at the request of any of the holders of any Debt Securities only
after those holders have offered the trustee indemnity reasonably satisfactory
to it.

   The holders of a majority in principal amount of Debt Securities of any
series have the right to waive past defaults under the Indenture that relate to
that series except for a default in the payment on the Debt Securities or a
provision that can only, under the Indenture, be modified or amended if all
holders that are affected consent.

   In most cases, holders of a majority in principal amount of the outstanding
Debt Securities of a series (or of all Debt Securities affected, voting as one
class) may direct the time, method and place of:

  . conducting any proceeding for any remedy available to the trustee; and

  . exercising any trust or power conferred on the trustee.

   The Indenture requires us to file each year with the trustee a written
statement as to our compliance with the covenants contained in the Indenture.

                                       10


Modification and Waiver

   We may amend or supplement the Indenture if the holders of a majority in
principal amount of the outstanding Debt Securities of all series that the
amendment or supplement affects (acting as one class) consent to it. Without
the consent of the holder of each Debt Security affected, however, no
modification may:

  . reduce the principal of the Debt Security or change its stated maturity;

  . reduce the rate of or change the time for payment of interest on the Debt
    Security;

  . reduce any premium payable on the redemption of the Debt Security or
    change the time at which the Debt Security may or must be redeemed;

  . change any obligation to pay additional amounts on the Debt Security;

  . impair the holder's right to institute suit for the enforcement of any
    payment on the Debt Security;

  . impair the holder's right to convert or exchange any Debt Security;

  . reduce the percentage of principal amount of Debt Securities whose
    holders must consent to an amendment to or supplement of the Indenture;

  . reduce the percentage of principal amount of Debt Securities necessary to
    waive compliance with some of the provisions of the Indenture; or

  . modify provisions relating to amendment or waiver, except to increase
    percentages or to provide that other provisions of the Indenture cannot
    be amended or waived without the consent of each holder affected.

   We may amend or supplement the Indenture or waive any provision of it
without the consent of any holders of Debt Securities in various circumstances,
including:

  . to provide for the assumption of our obligations under the Indenture and
    the Debt Securities by a successor;

  . to add covenants that would benefit the holders of any Debt Securities or
    to surrender any of our rights or powers;

  . to provide for the issuance of additional securities, including Debt
    Securities of a particular series, under the Indenture;

  . to add events of default;

  . to provide any security for or guarantees of any series of Debt
    Securities;

  . to provide for the form or terms of any series of Debt Securities;

  . to appoint a successor trustee or to provide for the administration of
    the trusts under the Indenture by more than one trustee;

  . to cure any ambiguity, omission, defect or inconsistency that does not
    adversely affect the interests of the holders of outstanding Debt
    Securities of any series;

  . to make any change to the extent necessary to permit or facilitate
    defeasance or discharge of any series of Debt Securities that does not
    adversely affect the interests of the holders of outstanding Debt
    Securities of any series; or

  . to make any change that does not affect the rights of any holder.

   The holders of a majority in principal amount of the outstanding Debt
Securities may waive our obligations to comply with various covenants,
including those relating to:

  . our obligation to secure the Debt Securities in the event of mergers,
    consolidations and sales of assets;

  . corporate existence; and

  . the restrictions on Liens and Sale/Leaseback Transactions.

                                       11


Defeasance

   When we use the term defeasance, we mean discharge from some or all of our
obligations under the Indenture. If we deposit with the trustee funds or
government securities the maturing principal and interest of which is
sufficient to make payments on the Debt Securities of a series on the dates
those payments are due and payable, then, at our option, either of the
following will occur:

  . "legal defeasance," which means that we will be discharged from our
    obligations with respect to the Debt Securities of that series; or

  . "covenant defeasance," which means that we will no longer have any
    obligation to comply with the restrictive covenants under the Indenture
    and any other restrictive covenants that apply to that series of the Debt
    Securities, and the related events of default will no longer apply to us.

   If we defease a series of Debt Securities, the holders of the Debt
Securities of the series affected will not be entitled to the benefits of the
Indenture, except for our obligations to pay additional amounts, if any, to
provide temporary Debt Securities, to register the transfer or exchange of Debt
Securities, to replace stolen, lost or mutilated Debt Securities or to maintain
paying agencies and hold moneys for payment in trust. In the case of covenant
defeasance, our obligation to pay principal, premium and interest on the Debt
Securities will also survive.

   Unless we inform you otherwise in the prospectus supplement, we will be
required to deliver to the trustee an opinion of counsel that the deposit and
related defeasance would not cause the holders of the Debt Securities to
recognize income, gain or loss for federal income tax purposes. If we elect
legal defeasance, that opinion of counsel must be based upon a ruling from the
Internal Revenue Service or a change in law to that effect.

Governing Law

   New York law governs the Indenture and the Debt Securities.

Trustee

   The Indenture contains limitations on the right of the trustee, if it
becomes one of our creditors, to obtain payment of claims or to realize on
property received for those claims, as security or otherwise. The trustee is
permitted to engage in other transactions with us. If, however, it acquires any
conflicting interest, it must eliminate that conflict or resign.

Form, Exchange, Registration and Transfer

   We will issue the Debt Securities in registered form, without interest
coupons. We will not charge a service charge for any registration of transfer
or exchange of the Debt Securities. We may, however, require the payment of any
tax or other governmental charge payable for that registration.

   Holders may exchange Debt Securities of any series for other Debt Securities
of the same series, the same total principal amount and the same terms but in
different authorized denominations in accordance with the Indenture. Holders
may present Debt Securities for registration of transfer at the office of the
security registrar or any transfer agent we designate. The security registrar
or transfer agent will effect the transfer or exchange when it is satisfied
with the documents of title and identity of the person making the request.

   We have appointed the trustee as security registrar for the Debt Securities.
If a prospectus supplement refers to any transfer agents initially designated
by us, we may at any time rescind that designation or approve a change in the
location through which any transfer agent acts. We are required to maintain an
office or agency for transfers and exchanges in each place of payment. We may
at any time designate additional transfer agents for any series of Debt
Securities.

                                       12


   In the case of any redemption, neither the security registrar nor the
transfer agent will be required to register the transfer or exchange of any
Debt Security either:

  . during a period beginning 15 business days prior to the mailing of the
    relevant notice of redemption and ending on the close of business on the
    day of mailing of that notice; or

  . if we have called the Debt Security for redemption in whole or in part,
    except the unredeemed portion of any Debt Security being redeemed in
    part.

Payment and Paying Agents

   Unless we inform you otherwise in a prospectus supplement, payments on the
Debt Securities will be made in U.S. dollars at the office of the trustee. At
our option, however, we may make payments by check mailed to the holder's
registered address or, for global Debt Securities, by wire transfer. Unless we
inform you otherwise in a prospectus supplement, we will make interest payments
to the person in whose name the Debt Security is registered at the close of
business on the record date for the interest payment.

   Unless we inform you otherwise in a prospectus supplement, we will designate
the trustee as our paying agent for payments on Debt Securities issued under
the Indenture. We may at any time designate additional paying agents or rescind
the designation of any paying agent or approve a change in the office through
which any paying agent acts.

   Subject to the requirements of any applicable abandoned property laws, the
trustee and paying agent will pay to us upon written request any money they are
holding for payments on the Debt Securities that remain unclaimed for two years
after the date upon which that payment has become due. After payment to us,
holders entitled to the money must look to us for payment. In that case, all
liability of the trustee or paying agent with respect to that money will cease.

Book-Entry Debt Securities

   We may issue the Debt Securities of a series in the form of one or more
global Debt Securities that would be deposited with a depositary or its nominee
identified in the prospectus supplement. We may issue global Debt Securities in
either temporary or permanent form. We will describe in the prospectus
supplement the terms of any depositary arrangement and the rights and
limitations of owners of beneficial interests in any global Debt Security.

                          DESCRIPTION OF CAPITAL STOCK

General

   We are authorized to issue a total of 400,000,000 shares of all classes of
stock. Of those authorized shares, 300,000,000 are shares of Common Stock, par
value $0.01 per share, 59,543,979 shares of which were outstanding as of June
11, 2001, and 100,000,000 are shares of Preferred Stock, par value $0.01 per
share. Of the Preferred Stock, there are 20,000,000 shares designated as Series
A Convertible Preferred Stock, of which 19,946,448 shares were outstanding at
June 11, 2001, 30,000,000 shares designated as Series B Convertible Preferred
Stock, none of which were outstanding, and 1,000,000 shares designated as
Series C Preferred Stock, none of which were outstanding.

   The additional shares of our authorized stock available for issuance might
be issued at times and under circumstances so as to have a dilutive effect on
earnings per share and on the equity ownership of the holders of our Common
Stock. The ability of our board of directors to issue additional shares of
stock could enhance the board's ability to negotiate on behalf of the
shareholders in a takeover situation but could also be used by the board to
make a change-in-control more difficult, thereby denying shareholders the
potential to sell their shares at a premium and entrenching current management.
The following description is a summary of the

                                       13


material provisions of our capital stock. You should refer to our certificate
of incorporation and by-laws for additional information.

Common Stock

   On May 17, 2001, our shareholders approved a two-for-one stock split of our
Common Stock to be effected by the issuance of one additional share of Common
Stock for each outstanding share to holders of record on May 23, 2001, with
distribution of the split shares on June 11, 2001. As of June 11, 2001, there
were approximately 14,473 holders of record. The issued and outstanding shares
of Common Stock are validly issued, fully paid and non-assessable. Subject to
any preferential rights of any prior ranking class or series of capital stock,
including the Preferred Stock, holders of shares of Common Stock are entitled
to receive dividends on that stock, payable either in cash, property or shares
out of assets legally available for distribution when, as and if authorized and
declared by our board of directors and to share ratably in our assets legally
available for distribution to our shareholders in the event of liquidation,
dissolution or winding-up. Subject to various exceptions, we will not be able
to pay any dividend or make any distribution of assets on shares of our Common
Stock until we pay dividends on any shares of Preferred Stock then outstanding
with dividend or distribution rights senior to our Common Stock. Dividends on
our Series A Convertible Preferred Stock and Series B Convertible Preferred
Stock are not cumulative.

   Holders of our Common Stock are entitled to one vote per share on all
matters voted on by our shareholders, including the election of directors. Our
certificate of incorporation does not provide for cumulative voting for the
election of directors, which means that holders of more than one-half of the
outstanding shares of our voting securities will be able to elect all of the
directors then standing for election and holders of the remaining shares will
not be able to elect any director.

   Our board of directors may make rules and regulations concerning the
transfer of shares of our Common Stock from time to time, in accordance with
our by-laws.

   Holders of our Common Stock will have no conversion, sinking fund or
redemption rights.

   Some provisions of the Oklahoma General Corporation Act, our certificate of
incorporation and our by-laws may discriminate against holders of a substantial
amount of the shares of our Common Stock. Similarly, some provisions of our
certificate of incorporation and our by-laws may have the effect of delaying,
deferring or preventing a change-in-control with respect to an extraordinary
corporate transaction, such as a merger, reorganization, tender offer, sale or
transfer of substantially all of our assets.

Shareholder Rights Agreement

   Under Oklahoma law, every corporation may create and issue rights entitling
the holders of those rights to purchase from the corporation shares of its
capital stock of any class or classes, subject to any provisions in its
certificate of incorporation. The price and terms of the shares must be stated
in the certificate of incorporation or in a resolution adopted by the board of
directors for the creation or issuance of those rights.

   In 1997, we entered into a Shareholder Rights Agreement. As with most
shareholder rights agreements, the terms of our Shareholder Rights Agreement
are complex and not easily summarized, particularly as they relate to the
acquisition of our Common Stock and to exercisability. This summary, which
summarizes the material provisions of the Shareholder Rights Agreement, may not
contain all of the information that is important to you. Accordingly, you
should carefully read our Shareholder Rights Agreement, which has been filed as
an exhibit to the registration statement of which this prospectus forms a part.

   Our Shareholder Rights Agreement provides that each share of our Common
Stock outstanding as of November 26, 1997 and issued between that date and a
date determined pursuant to the Shareholder Rights Agreement, will have one
right to purchase one one-hundredth of a share of Preferred Stock, designated
as

                                       14


Series C Preferred Stock, attached to it, at a purchase price of $40 per one
one-hundredth of a share of Preferred Stock, subject to adjustment, as
described below.

   Initially, the rights under our Shareholder Rights Agreement are attached to
outstanding certificates representing our Common Stock and no separate
certificates representing the rights will be distributed. The rights will
separate from our Common Stock and be represented by separate certificates on
the earlier of the first date someone acquires beneficial ownership (as defined
in the Shareholder Rights Agreement) of 15% or more of our outstanding Common
Stock, subject to various exceptions, or approximately 10 days after someone
commences or indicates an intent to commence a tender offer or exchange offer
for 15% of our Common Stock. The person or group that acquires or indicates an
intent to acquire stock as described in the immediately preceding sentence is
referred to as an acquiring person.

   Our Shareholder Rights Agreement specifically excludes as an acquiring
person, among others,

  . any member of the shareholder group (which consists of Western Resources,
    Inc., any Western Resources affiliate and any person with whom Western
    Resources or any of its affiliates is part of a partnership, limited
    partnership, syndicate or other group of persons acquiring, holding,
    voting or disposing of any voting securities which would be required
    under Section 13(d) of the Securities Exchange Act of 1934 to file a
    statement on Schedule 13D with the Securities and Exchange Commission)
    but only to the extent of shares of our Common Stock held or acquired by
    the shareholder group member in accordance with the Shareholder Agreement
    with Western Resources and provided that this exemption permanently
    expires when the ownership percentage of Western Resources and its
    affiliates first falls below 10%, which ownership percentage is
    determined by calculating the voting power represented by all of our
    securities beneficially owned by Western Resources and its affiliates
    after giving effect to the conversion of all convertible securities into
    shares of our Common Stock or other voting securities; and

  . any transferee who acquires beneficial ownership of shares of our Common
    Stock from the shareholder group pursuant to provisions of the
    Shareholder Agreement with Western Resources or who acquires beneficial
    ownership of less than 5% of our Common Stock in a public offering
    pursuant to the Shareholder Agreement, but only to the extent of shares
    of our Common Stock acquired in accordance with the terms of the
    Shareholder Agreement. The transferee will be considered an acquiring
    person upon the concurrent or subsequent acquisition by that transferee,
    or its affiliates or associates, of any additional shares of our Common
    Stock if, after giving effect to the acquisition, and taking into account
    all shares beneficially owned by the transferee including the shares
    acquired from the shareholder group, the transferee would be considered
    an acquiring person but for this summarized provision.

   All shares of our Common Stock issued prior to the date the rights separate
from the Common Stock will be issued with the rights attached. The rights are
not exercisable until the date the rights separate from the Common Stock. The
rights will expire on November 26, 2007, unless we redeem or exchange them at
an earlier time or upon the consummation of specified transactions.

   If a person or group becomes an acquiring person, then each right not owned
by that acquiring person or its affiliates, associates or transferees, will
entitle its holder to purchase, within specified time periods and at the
right's then current purchase price, shares of our Common Stock (or, in limited
circumstances, one one-hundredths of a share of Preferred Stock) as equals the
result obtained by:

  . multiplying the then current purchase price by the then number of one
    one-hundredths of a share of our preferred stock for which a right was
    exercisable immediately prior to the first occurrence of a person or
    group becoming an acquiring person; and

  . dividing that product by 50% of the then current per share market price
    of our Common Stock on the date of the first occurrence.

   If, after a person or group becomes an acquiring person, and:

  . we are involved in a merger or consolidation with an interested
    shareholder or with any other person in a case where all holders of our
    Common Stock are not treated alike; or

                                       15


  . we sell or transfer more than 50% of our assets or earning power to an
    interested stockholder or other person or, to any other person in a case
    where all holders of our Common Stock are not treated alike,

each right will entitle the holder to purchase, at the right's then current
purchase price, shares of Common Stock of the acquiring company as equal the
result obtained by:

  . multiplying the then current purchase price by the number of one one-
    hundredths of a share of our Preferred Stock for which a right is then
    exercisable; and

  . dividing the product by 50% of the then current per share market price of
    the Common Stock of the acquiring company.

   We may, at our option, at any time after any person becomes an acquiring
person, exchange all or part of the then outstanding and exercisable rights for
our Common Stock (or shares of our other equity securities, including one one-
hundredths of a share of Preferred Stock, with equivalent rights and privileges
as our Common Stock) at an exchange ratio of one share of our Common Stock per
right, subject to adjustment, until the time that any person, together with its
affiliates and associates, has become the beneficial owner of 50% or more of
our outstanding Common Stock.

   Our board of directors may, at its option, redeem all of the outstanding
rights under our Shareholder Rights Agreement prior to the earlier of (1) the
time that an acquiring person obtains 15% or more of our outstanding stock or
(2) the final expiration date of the rights. The redemption price under our
Shareholder Rights Agreement is $0.005 per right, subject to adjustment. The
right to exercise the rights will terminate upon the action of our board
ordering the redemption of the rights and the only right of the holders of the
rights will be to receive the redemption price.

   Holders of rights will have no rights as our stockholders, including the
right to vote or receive dividends, simply by virtue of holding the rights.

   Our Shareholder Rights Agreement contains rights that have anti-takeover
effects. The rights may cause substantial dilution to a person or group that
attempts to acquire us without conditioning the offer on a substantial number
of rights being acquired. Accordingly, the existence of the rights may deter
acquirors from making takeover proposals or tender offers. However, the rights
are not intended to prevent a takeover, but rather are designed to enhance the
ability of our board to negotiate with an acquiror on behalf of all the
shareholders. In addition, the rights should not interfere with a proxy
contest.

Preferred Stock

   Our board of directors is authorized to issue shares of Preferred Stock, in
one or more series or classes, and to fix for each series or class the
preferences, conversion or other rights, voting powers, restrictions,
limitations as to dividends, qualifications, or terms or redemption, as are
permitted by Oklahoma law and are as stated in the resolution or resolutions
adopted by the board providing for the issuance of shares of that series or
class.

   One series of Preferred Stock, designated Series A Convertible Preferred
Stock, is outstanding. In addition, our board has authorized a series
designated as Series B Preferred Stock, and a series designated as Series C
Preferred Stock which relates to our Shareholder Rights Agreement. The
following is a description of those series.

 Convertible Preferred Stock

   Designation and Amount. There are 20,000,000 shares of Series A Convertible
Preferred Stock and 30,000,000 shares of Series B Convertible Preferred Stock
authorized. All outstanding shares of Series A Convertible Preferred Stock are
currently held by Western Resources and its affiliates. There are no currently

                                       16


outstanding shares of Series B Convertible Preferred Stock. The previously
outstanding shares of Series B Convertible Preferred Stock were owned by
Western Resources and its affiliates. We reacquired those shares in accordance
with the Shareholder Agreement with Western Resources described below. Shares
of Series B Convertible Preferred Stock could be issued in the future to
Western Resources or its affiliates as provided in the Shareholder Agreement.
Dividends on Series A Convertible Preferred Stock are not cumulative and
dividends on Series B Convertible Preferred Stock, if issued, would not be
cumulative.

   Rank. With respect to dividend rights and distribution of assets upon
liquidation, dissolution or winding up of affairs, the Convertible Preferred
Stock ranks senior to shares of our Common Stock, or any class of our equity
securities that by its terms is junior to the Convertible Preferred Stock, and
will not rank junior with respect to any class or series of Preferred Stock
that we may issue, unless the holders of 66 2/3% of the outstanding shares of
the Convertible Preferred Stock consent to the creation of the class or any
security convertible into shares of that class or series. We have agreed not to
create, authorize or reclassify any authorized stock into any class of capital
stock ranking prior to the Convertible Preferred Stock.

   Dividends. We will pay or declare preferential cash dividends quarterly on
each share of Convertible Preferred Stock but those dividends are not
cumulative to the extent they are not paid on any dividend payment date. If we
do not pay dividends on the Convertible Preferred Stock on the dividend payment
date for any dividend period, dividends will not be subsequently paid for that
dividend period.

   The dividend amount on each share of Series A Convertible Preferred Stock,
with respect to each dividend declared on our Common Stock, will be equal to 3
times the dividend amount declared on each share of our Common Stock for that
dividend period, as adjusted appropriately to reflect any stock split, stock
dividend, reverse stock split, reclassification or any transaction with
comparable effect upon our Common Stock. Subsequent to November 26, 2002, the
dividend amount on each share of Series A Convertible Preferred Stock will be
equal to 2.5 times the dividend amount declared on each share of our Common
Stock for that dividend period, as so adjusted. In no event, however, will the
aggregate annual dividend amount payable per share of Series A Convertible
Preferred Stock be less than $1.80 per share.

   The dividend amount on each share of Series B Convertible Preferred Stock
will be equal to 2.5 times the dividend amount declared on each share of our
Common Stock for each dividend period, as adjusted appropriately to reflect any
stock split, stock dividend, reverse stock split, reclassification or any
transaction with comparable effect upon our Common Stock. In no event, however,
will the aggregate annual dividend amount declared on each share of Series B
Convertible Preferred Stock prior to November 26, 2002, be less than $1.50 per
share and in no event will the aggregate annual dividend amount declared on
each share of Series B Convertible Preferred Stock following November 26, 2002,
be less than $1.80 per share.

   Liquidation Preference. The liquidation preference per share of Convertible
Preferred Stock will be equal to that payable per share of our Common Stock, as
adjusted appropriately to reflect any stock split or similar events, assuming
the conversion of all outstanding shares of Convertible Preferred Stock
immediately prior to the event triggering the liquidation preference, plus any
dividends then due with respect to the Convertible Preferred Stock.

   Neither our merger or consolidation into or with one or more other
corporations, nor the voluntary sale, conveyance, exchange or transfer of all
or substantially all of our property or assets will be deemed to be a
liquidation, dissolution or winding up, voluntary or involuntary, for the
purposes of triggering a liquidation preference, unless that voluntary sale,
conveyance, exchange or transfer is in connection with a dissolution or winding
up of our business.

   Redemption. We have no right to redeem any shares of Convertible Preferred
Stock.

   Conversion Rights. After the occurrence of a regulatory change (which means
that either the Public Utility Holding Company Act of 1935 has been repealed,
modified, amended or otherwise changed, or Western

                                       17


Resources has received or is entitled to an exemption under that act or has
registered under that act so that Western Resources may fully and legally
exercise its rights under the Shareholder Agreement described below), holders
of shares of Convertible Preferred Stock will have the right, at their option,
to convert each share into two fully paid and nonassessable shares of our
Common Stock, as adjusted appropriately to reflect any stock split, stock
dividend, reverse stock split, reclassification or any transaction with
comparable effect upon our Common Stock. Conversion will, however, be automatic
and mandatory upon the transfer of the beneficial ownership of any share of
Convertible Preferred Stock to any person other than Western Resources or its
affiliates. Mandatory conversion will be at the same rate of exchange as that
applicable to an optional conversion.

   We have agreed that we will have at all times reserved and kept available,
out of our authorized and unissued stock, shares of our Common Stock in an
amount sufficient for the conversion of all shares of Convertible Preferred
Stock then outstanding.

   Anti-dilution Provisions. The number of shares of our Common Stock into
which each share of Convertible Preferred Stock is convertible, the dividend
amount payable on each share of Convertible Preferred Stock, and the
liquidation preference attached to each share of Convertible Preferred Stock
will be subject to adjustments for stock splits, stock dividends, reverse stock
splits or any transaction with comparable effect upon our Common Stock.

   Voting Rights. Holders of shares of Convertible Preferred Stock will be
entitled to vote together with holders of shares of our Common Stock, as a
single class, with respect to:

  . any proposed amendment to our certificate of incorporation or by-laws
    that would reasonably have the effect of modifying in any way the
    amendment by which we opted out of Sections 1145 through 1155 of Title 18
    of the Oklahoma Statutes, which relates to control share acquisitions, or
    would reasonably cause us to become subject to:

    . the control share acquisition statute; or

    . any other provisions that are substantially similar to the control
      share acquisition statute;

  . any proposal relating to the amendment by which we opted out of Sections
    1145 through 1155 of Title 18 of the Oklahoma Statutes; and

  . any transaction or series of transactions that, if consummated, would
    constitute a change-in-control.

   With respect to those matters, each share of Convertible Preferred Stock
will carry a number of votes equal to the number of votes carried by the number
of shares of our Common Stock issuable upon conversion of one share of
Convertible Preferred Stock.

   Holders of Convertible Preferred Stock will not be entitled to vote in any
election of directors to our board or on any matter submitted to our
shareholders other than the foregoing and other than as required by law.

   Potential Anti-Takeover Effects of the Convertible Preferred Stock. The
issuance of our Common Stock into which the Convertible Preferred Stock is
convertible or exchangeable, together with the provisions of the Shareholder
Agreement that we entered into with Western Resources that are described below,
may have anti-takeover implications. The combined effect of these issuances and
the Shareholder Agreement may be to discourage or render more difficult a
merger, tender offer or proxy contest involving us, or to deter a third party
from seeking to acquire control of us.

 Series C Preferred Stock

   In connection with our Shareholder Rights Agreement, our board of directors
established a series of preferred stock, designated as Series C Preferred
Stock. Holders of the Series C Preferred Stock are entitled to receive, in
preference to the holders of our Common Stock, quarterly dividends payable in
cash on the last day

                                       18


of each fiscal quarter in each year, or those other dates as our board of
directors deems appropriate, in an amount per share equal to the greater of $1
or subject to adjustment, 100 times the aggregate per share amount of all cash
dividends, and 100 times the aggregate per share amount (payable in kind) of
all non-cash dividends, other than a dividend payable in our Common Stock,
payable on our Common Stock. The Series C Preferred Stock dividends are
cumulative but do not bear interest. Shares of Series C Preferred Stock are not
redeemable. Subject to adjustment, each share of Series C Preferred Stock
entitles the holder thereof to 100 votes on all matters submitted to a vote of
our shareholders and during a certain dividend default period, holders of the
Series C Preferred Stock have other special voting rights. If we liquidate,
dissolve or wind up our affairs, holders of Series C Preferred Stock are
entitled to priority over the holders of shares of our Common Stock or other
junior ranking stock.

   For each share of our Common Stock the holder has the right to purchase one
one-hundredth of a share of Series C Preferred Stock upon the happening of
change-in-control and similar transactions as described in the Shareholder
Rights Agreement.

Preemptive Rights

   No holder of any shares of any class of our stock has any preemptive or
preferential right to acquire or subscribe for any unissued shares of any class
of stock or any unauthorized securities, convertible into or carrying any
right, option or warrant to subscribe for or acquire shares of any class of
stock. Under the Shareholder Agreement, however, the shareholder group has top-
up rights to acquire additional shares of our stock in limited circumstances
described below.

Shareholder Agreement

   We are party to a Shareholder Agreement with Western Resources. The
following description is a summary of the material provisions of our
Shareholder Agreement. You should refer to the Shareholder Agreement, a copy of
which is filed as an exhibit to the registration statement of which this
prospectus is a part, for additional information.

 Standstill

   The Shareholder Agreement provides, among other things, that Western
Resources and its affiliates are prohibited from taking various actions,
including, without limitation:

  . prior to the occurrence of a regulatory change, the acquisition of our
    voting securities that would cause the shareholder group to have
    securities representing more than 9.9% of our total outstanding voting
    power;

  . at any time, the acquisition of securities that would cause the
    shareholder group's total ownership percentage (including shares of
    Common Stock issuable upon conversion of shares of Convertible Preferred
    Stock or other securities) to exceed the maximum ownership percentage,
    which is a total ownership percentage of 45%, less the voting power
    represented by all voting securities transferred by the shareholder group
    during the term of the Shareholder Agreement represented by any shares of
    Convertible Preferred Stock converted into shares of our Common Stock
    contemporaneously with the transfer pursuant to the Shareholder
    Agreement;

  . the deposit of our equity securities in a voting trust or subjecting of
    those equity securities to any similar arrangement or proxy with respect
    to the voting of those equity securities;

  . the commencement of a merger, acquisition or other business combination
    transaction relating to us; and

  . engagement in any other action, either alone or in concert with others,
    to seek to control or influence our management, board of directors or
    policies.

                                       19


 Top-Up Rights

   In the event that the shareholder group's ownership percentage (including
shares of Common Stock issuable upon conversion of shares of Convertible
Preferred Stock or other securities) falls below the maximum ownership
percentage, Western Resources has rights to acquire additional equity
securities to restore the maximum ownership percentage of the shareholder group
to the maximum ownership percentage. Western Resources may exercise those
rights:

  . by purchasing our Common Stock in the open market or otherwise (and, to
    the extent those purchases would cause the shareholder group's voting
    ownership percentage to exceed 9.9% prior to a regulatory change,
    exchanging each of those shares for one half of a share of Series B
    Convertible Preferred Stock issued by us, subject to adjustment to
    reflect any stock split, combination or similar transaction);

  . in some events where the reduction in the shareholder group's total
    ownership percentage (including shares of Common Stock issuable upon
    conversion of shares of Convertible Preferred Stock or other securities)
    is caused by a dilutive issuance of our securities, by requiring us to
    issue to Western Resources at the issue price per share of the dilutive
    issuance, prior to a regulatory change, additional shares of our Common
    Stock and, to the extent that issuance would cause the shareholder
    group's voting ownership percentage to exceed 9.9%, Series B Convertible
    Preferred Stock sufficient to restore the shareholder group's total
    ownership percentage (including shares of Common Stock issuable upon
    conversion of shares of Convertible Preferred Stock or other securities)
    to the maximum ownership percentage; or

  . in the case of a dilutive issuance that is the result of an acquisition
    or other business combination transaction, by merger or otherwise, by
    requiring us to issue to Western Resources shares of our Common Stock
    sufficient to restore the shareholder group's total ownership percentage
    to the maximum ownership percentage minus 10%.

 Restrictions on Transfer

   During the term of the Shareholder Agreement, the shareholder group is
prohibited, without the prior written consent of a majority of our independent
directors, from transferring any of our equity securities except:

  . transfers of equity securities representing voting power of less than 5%
    provided that the transferee does not have a voting ownership percentage
    of 5% or more immediately prior to the transfer;

  . in a bona fide underwritten public offering pursuant to the Registration
    Rights Agreement that we entered into with Western Resources;

  . pursuant to a pro rata distribution to Western Resources' shareholders;
    and

  . pursuant to a procedure that permits Western Resources to transfer equity
    securities representing 5% or more of our voting power, provided that we
    have been given notice thereof, and have failed, within a specified
    period of time, to purchase from Western Resources the equity securities
    proposed to be sold at a cash purchase price per share equal to 98.5% of
    the then current market price for our Common Stock.

   In addition, in the case of a bona fide third party tender offer for
securities, Western Resources may tender into that offer a proportionate amount
of its equity securities.

 Voting

   During the term of the Shareholder Agreement, Western Resources has agreed
to vote, and to cause each of its affiliates to vote, all voting securities
that it owns as follows:

  . with respect to the election of directors, Western Resources will vote
    its voting securities in favor of the election of all candidates for
    director nominated by our board of directors;

                                       20


  . with respect to any proposal initiated by any of our shareholders
    relating to the redemption of the rights issued pursuant to the
    Shareholder Rights Agreement or any modification of the Shareholder
    Rights Agreement (other than nonbinding precatory resolutions), Western
    Resources will, and will cause each member of the shareholder group to,
    vote all voting securities beneficially owned by Western Resources or any
    member of the shareholder group in accordance with the recommendation of
    our board;

  . with respect to transactions constituting a change-in-control or with
    respect to any proposal relating to the opt-out amendment, Western
    Resources may vote any or all of the voting securities and Convertible
    Preferred Stock (which, as described above, has the right in such
    circumstances to vote together with our Common Stock on a two votes per
    share basis, as adjusted to reflect our recent stock split and subject to
    adjustment to reflect any further stock split or similar events) held by
    the shareholder group in its sole discretion;

  . with respect to any proposed amendment to our certificate of
    incorporation or by-laws that would reasonably have the effect of
    modifying in any way the opt-out amendment or would reasonably cause us
    to become subject to the control share acquisition statute or any other
    provisions that are substantially similar to the control share
    acquisition statute, Western Resources or any member of the shareholder
    group has the right to abstain or vote against such amendment; and

  . with respect to all other matters,

    . prior to the occurrence of a regulatory change, Western Resources may
      vote any voting securities held by the shareholder group in Western
      Resources' sole discretion; and

    . after the occurrence of a regulatory change, Western Resources may
      vote in its sole discretion up to 9.9% of our outstanding voting
      power and Western Resources must vote any other voting securities
      owned by it in the same proportion as all voting securities voted on
      the other matter are voted by our other shareholders.

 Board Representation

   Prior to a regulatory change, Western Resources is entitled to designate two
members of our Board of Directors. After a regulatory change, subject to
transition provisions, Western Resources is entitled to designate up to one-
third of our Board of Directors.

 Term; Buy/Sell Option

   The Shareholder Agreement terminates if, among other things:

  . our quarterly dividend on our Common Stock falls below $0.15 per share
    (as adjusted to reflect any stock split or similar events) in any five
    quarters or we fail to pay the stated quarterly dividend on any series of
    Convertible Preferred Stock in any five quarters;

  . the shareholder group's total ownership percentage falls below 9.9% at
    any time; or

  . the shareholder group's total ownership percentage falls below 30% at any
    time after November 26, 2012, which is the 15th anniversary of the
    signing of the Shareholder Agreement.

   In addition, on the 15th and each subsequent anniversary of the signing of
the Shareholder Agreement, each of Western Resources and us, on behalf of our
shareholders, has the right to buy from or sell to the other, by purchase, sale
or credible tender offer, as appropriate, all outstanding shares of our capital
stock beneficially owned by the selling party (which, in our case, means our
shareholders other than Western Resources and the shareholder group). In
addition, if at any time after the occurrence of a regulatory change, we
believe in good faith that Western Resources' regulatory status as modified by
that regulatory change would place an unreasonable restriction on the
implementation of strategic business plans, we may immediately initiate our
buy/sell rights.

                                       21


Registration Rights Agreement

   In 1997, we entered into a Registration Rights Agreement that enables
Western Resources to require that we register its shares of our Common Stock,
including shares of our Common Stock obtained upon conversion of its shares of
Convertible Preferred Stock, under the Securities Act of 1933. Under the
Registration Rights Agreement, Western Resources is entitled, subject to the
conditions set forth therein, to:

  . demand registration rights, whereby Western Resources can require us to
    file a registration statement under the Securities Act of 1933
    registering its shares of our Common Stock; and

  . piggy-back registration rights, whereby Western Resources can require
    that we include any or all of its shares of our Common Stock in a
    registration statement that we have proposed to file under the Securities
    Act of 1933.

Oklahoma Law

 Oklahoma Takeover Statute

   We are subject to Section 1090.3 of the Oklahoma General Corporation Act. In
general, Section 1090.3 prevents an "interested shareholder" from engaging in a
"business combination" with an Oklahoma corporation for three years following
the date that person became an interested shareholder, unless:

  . prior to the date that person became an interested shareholder, our board
    of directors approved the transaction in which the interested shareholder
    became an interested shareholder or approved the business combination;

  . upon consummation of the transaction that resulted in the interested
    shareholder's becoming an interested shareholder, the interested
    shareholder owns at least 85% of our voting stock outstanding at the time
    the transaction commenced, excluding stock held by directors who are also
    officers of the corporation and stock held by certain employee stock
    plans; or

  . on or subsequent to the date of the transaction in which that person
    became an interested shareholder, the business combination is approved by
    the board of directors of the corporation and authorized at a meeting of
    shareholders by the affirmative vote of the holders of two-thirds of the
    outstanding voting stock of the corporation not owned by the interested
    shareholder.

   Section 1090.3 defines a "business combination" to include:

  . any merger or consolidation involving the corporation and an interested
    shareholder;

  . any sale, transfer, pledge or other disposition involving an interested
    shareholder of 10% or more of the assets of the corporation;

  . subject to limited exceptions, any transaction that results in the
    issuance or transfer by the corporation of any stock of the corporation
    to an interested shareholder;

  . any transaction involving the corporation that has the effect of
    increasing the proportionate share of the stock of any class or series of
    the corporation beneficially owned by the interested shareholder; or

  . the receipt by an interested shareholder of any loans, guarantees,
    pledges or other financial benefits provided by or through the
    corporation.

   For purposes of Section 1090.3, the term "corporation" also includes our
majority-owned subsidiaries. In addition, Section 1090.3, defines an
"interested shareholder" as an entity or person beneficially owning 15% or more
of our outstanding voting stock and any entity or person affiliated with or
controlling or controlled by that entity or person.

 Oklahoma Control Share Act

   Our certificate of incorporation provides that we are not subject to the
Oklahoma Control Share Act. With exceptions, this act prevents holders of more
than 20% of the voting power of the stock of an Oklahoma

                                       22


corporation from voting their shares. If we were to become subject to the
Oklahoma Control Share Act in the future, this provision may delay the time it
takes anyone to gain control of us.

Certificate of Incorporation and By-laws

 Exculpation

   Our certificate of incorporation provides that our directors and officers
will not be personally liable for monetary damages for any action taken, or any
failure to take any action, unless:

  . the director or officer has breached his or her duty of loyalty to the
    corporation or its shareholders;

  . the breach or failure to perform constitutes an act or omission not in
    good faith or which involves intentional misconduct or a knowing
    violation of law;

  . the director served at the time of payment of an unlawful dividend or an
    unlawful stock purchase or redemption, unless the director was absent at
    the time the action was taken; or

  . the director or officer derived an improper personal benefit from the
    transaction.

 Indemnification

   We will generally indemnify any person who was, is, or is threatened to be
made, a party to a proceeding by reason of the fact that he or she:

  . is or was our director, officer, employee or agent; or

  . while our director, officer, employee or agent is or was serving at our
    request as a director, officer, employee or agent of another corporation,
    partnership, joint venture, trust or other enterprise.

   Any indemnification of our directors, officers or others pursuant to the
foregoing provisions for liabilities arising under the Securities Act of 1933
are, in the opinion of the Securities and Exchange Commission, against public
policy as expressed in the Securities Act of 1933 and are unenforceable.

 Shareholder Action; Special Meeting of Shareholders

   Our certificate of incorporation eliminates the ability of our shareholders
to act by written consent. Our by-laws provide that special meetings of our
shareholders may be called only by a majority of the members of our board of
directors.

 Advance Notice Requirements for Shareholder Proposals

   At any meeting of our shareholders, the only business that shall be brought
before the meeting is that which is brought:

  . pursuant to our notice of meeting;

  . by or at the discretion of our board of directors; or

  . by any of our shareholders of record at the time the notice is given, who
    shall be entitled to vote at the meeting and who complies with the notice
    procedures set forth herein.

   For business to be properly brought before a meeting by a shareholder
pursuant to the immediately preceding clause, the shareholder must have given
timely notice in writing to our secretary. To be timely as to an annual meeting
of shareholders, a shareholder's notice must be received at our principal
executive offices not less than 120 calendar days before the date our proxy
statement is released to shareholders in connection with the previous year's
annual meeting; provided however, that if the date of the meeting is changed by
more than 30 days from the date of the previous year's meeting, notice must be
received no later than the close of business on the 10th day following the
earlier of the day on which notice of the date of the meeting was mailed to

                                       23


shareholders or public disclosure of that date was made. To be timely as to a
special meeting of shareholders, a shareholder notice must be received not
later than the call of the meeting as provided in our by-laws. The shareholder
notice shall set forth as to each matter the shareholder proposes to bring
before the meeting:

  . a brief description of and the reasons for proposing the matter at the
    meeting;

  . the name and address, as they appear on our books, and the name and
    address of the beneficial owner, if any, on whose behalf the proposal is
    made;

  . the class and number of shares that are owned beneficially and of record
    by the shareholder of record and by the beneficial owner, if any, on
    whose behalf the proposal is made; and

  . any material interest of the shareholder of record and the beneficial
    owner, if any, on whose behalf the proposal is made, in the proposal.

   These provisions may impede shareholders' ability to bring matters before an
annual meeting of shareholders.

 Higher Vote for Some Business Combinations and Other Actions

   Subject to various exceptions, including acquiring 85% of the outstanding
shares less shares owned by related persons in a single transaction, a business
combination (including, but not limited to, a merger or consolidation, the
sale, lease, exchange, transfer or other distribution of our assets in excess
of $5,000,000, various issuances and reclassifications of securities and the
adoption of a plan or proposal for liquidation or dissolution) with or upon a
proposal by a related person, who is a person that is the direct or indirect
beneficial owner of more than 10% of the outstanding voting shares of our stock
(subject to various exceptions), and any affiliates of that person, shall
require, in addition to any approvals required by law, the approval of the
business combination by either:

  . a majority vote of all of the independent directors; or

  . the holders of at least 66 2/3% of the outstanding shares otherwise
    entitled to vote as a single class with the Common Stock to approve the
    business combination, excluding any shares owned by the related person.

   In addition, our certificate of incorporation provides that our by-laws may
only be adopted, amended or repealed by a majority of the board of directors or
by 80% of our shareholders, voting as a class. Our certificate of incorporation
also requires the affirmative vote of 80% of our shareholders to amend, repeal
or adopt provisions in our certificate of incorporation relating to, among
other things,

  . the number of directors and the manner of electing those directors,
    including the election of directors to newly created directorships;

  . provisions relating to changes in the by-laws;

  . a director's personal liability to us or our shareholders;

  . shareholder ratification of various contracts, transactions and acts; and

  . voting requirements for approval of business combinations.

 Transactions with Interested Parties

   Our certificate of incorporation provides that, in the absence of fraud, no
contract or other transaction will be affected or invalidated by the fact that
any of our directors are in any way interested in or connected with any other
party to the contract or transaction or are themselves parties to the contract
or transaction, provided that the interest is fully disclosed or otherwise
known to our board of directors at the meeting of the board at which the
contract or transaction is authorized or confirmed, and provided further that a
quorum of disinterested directors is present at the meeting of our board of
directors authorizing or confirming the contract or transaction and the
contract or transaction is approved by a majority of the quorum, and no
interested director votes on the

                                       24


contract or transaction. Any contract, transaction or act entered into or taken
by us or our board or any committee thereof that is ratified by a majority of a
quorum of the shareholders having voting power at any annual meeting, or any
special meeting called for that purpose, will be valid and binding as though
ratified by all of our shareholders. Any director may vote upon any contract or
other transaction between us and any subsidiary corporation without regard to
the fact that he is also a director of that subsidiary corporation. No contract
or agreement between us and any other corporation or party that owns a majority
of our capital stock or any subsidiary of that other corporation shall be made
or entered into without the affirmative vote of a majority of the whole board
of directors at a regular meeting of the board.

Transfer Agent and Registrar

   The transfer agent and registrar for our Common Stock is First Chicago Trust
Company of New York, in Jersey City, New Jersey.

                              PLAN OF DISTRIBUTION

   We may sell the Securities offered under this prospectus through
underwriters, agents or dealers or directly to purchasers.

Underwriters

   The applicable prospectus supplement will identify any agents or
underwriters and describe their compensation, including underwriting discount.
The prospectus supplement will also describe other terms of the offering,
including any discounts or concessions allowed or reallowed or paid to dealers
and any securities exchanges on which the offered Securities may be listed.

   The distribution of Securities under this prospectus may occur from time to
time in one or more transactions at a fixed price or prices, which may be
changed, at market prices prevailing at the time of sale, at prices related to
those prevailing market prices or at negotiated prices.

Agents and Direct Sales

   If the applicable prospectus supplement indicates, we will authorize dealers
or our agents to solicit offers by various institutions to purchase offered
Securities from us pursuant to contracts that provide for payment and delivery
on a future date. We must approve all institutions, but they may include, among
others:

  . commercial and savings banks;

  . insurance companies;

  . pension funds;

  . investment companies; and

  . educational and charitable institutions.

   The institutional purchaser's obligations under a contract will be subject
only to the condition that the purchase of the offered Securities at the time
of delivery is allowed by any laws that govern the purchaser. The dealers and
our agents will not be responsible for the validity or performance of the
contracts.

General Information

   Underwriters, dealers and agents participating in a sale of Securities may
be deemed to be underwriters as defined in the Securities Act of 1933, and any
discounts and commissions received by them and any profit realized by them on
resale of the Securities may be deemed to be underwriting discounts and
commissions

                                       25


under the Securities Act of 1933. We may have agreements with the agents,
underwriters and dealers to indemnify them against various civil liabilities,
including liabilities under the Securities Act of 1933, or to contribute to
payments that the agents, underwriters or dealers may be required to make as a
result of those civil liabilities.

   Unless we indicate differently in a prospectus supplement, we will not list
the Securities on any securities exchange. If we sell a security offered under
this prospectus to an underwriter for public offering and sale, the underwriter
may make a market for that security but is not obligated to do so. Therefore,
we cannot give any assurances to you concerning the liquidity of any security
offered under this prospectus.

   Agents and underwriters and their affiliates may be customers of, engage in
transactions with, or perform services for us or our subsidiary companies in
the ordinary course of business.

                                 LEGAL MATTERS

   The validity of the Securities will be passed upon for ONEOK by Gable &
Gotwals, Tulsa, Oklahoma. Any underwriters or agents will be advised about
other issues relating to any offering by Jones, Day, Reavis & Pogue, Chicago,
Illinois. Jones, Day, Reavis & Pogue will rely on Gable & Gotwals as to matters
of Oklahoma law. Jones, Day, Reavis & Pogue from time to time acts as counsel
to ONEOK.

                                    EXPERTS

   The consolidated financial statements of ONEOK and its subsidiaries as of
December 31, 2000, December 31, 1999 and August 31, 1999, and for the year
ended December 31, 2000, the years ended August 31, 1999 and 1998 and the four
months ended December 31, 1999 have been incorporated by reference herein in
reliance upon the report of KPMG LLP, independent certified public accountants,
incorporated by reference herein, and upon the authority of said firm as
experts in accounting and auditing. The report of KPMG LLP covering the
December 31, 2000 consolidated financial statements refers to a change in
accounting for energy trading contracts in 2000.

                                       26


                                    PART II.

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

   The following table sets forth the expenses in connection with the issuance
and distribution of the securities being registered, other than underwriting
discounts and commissions. All of the amounts shown are estimated, except the
Securities and Exchange Commission registration fee.


                                                                    
   Securities and Exchange Commission registration fee................ $110,000
   Legal fees and expenses............................................   40,000
   Printing and engraving.............................................   50,000
   Fees of accountants................................................   60,000
   Fees of trustee....................................................    7,000
   Rating agencies fees...............................................  286,000
   Blue sky fees and expenses.........................................    2,000
   Miscellaneous......................................................   10,000
                                                                       --------
                                                                       $565,000
                                                                       ========


Item 15. Indemnification of Directors and Officers.

   ONEOK, Inc. (the "Company"), as an Oklahoma corporation, is empowered by
section 1031 of the Oklahoma General Corporation Act, subject to the procedures
and limitations stated therein, to indemnify any person against expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement
actually and reasonably incurred by him in connection with any threatened,
pending or completed action, suit or proceeding in which such person is made or
threatened to be made a party by reason of his being or having been a director,
officer, employee or agent of the Company. The statute provides that
indemnification pursuant to its provisions is not exclusive of other rights of
indemnification to which a person may be entitled under any bylaw, agreement,
vote of shareholders, or disinterested directors, or otherwise. Article VIII of
the by-laws of the Company provides that directors and officers of the Company
shall be indemnified by the Company to the fullest extent permitted by Oklahoma
law as now or hereafter enforced, including the advance of related expenses. In
addition, indemnification agreements, the form of which has been previously
approved by the shareholders of the Company, have been entered into between the
Company and each of its directors and executive officers.

   The certificate of incorporation of the Company provides that a director of
the corporation shall not be personally liable to the corporation or its
shareholders for monetary damages for breach of fiduciary duty as a director,
except for liability for (i) any breach of the director's duty of loyalty to
the corporation or its shareholders, (ii) acts or omissions not in good faith
or which would involve intentional misconduct or a knowing violation of law,
(iii) payment of unlawful dividends or unlawful stock purchases or redemptions
or (iv) any transaction from which the director derived an improper personal
benefit.

   Pursuant to Article VIII of the by-laws of the Company, upon authorization
and determination (i) by the board of directors by a majority of a quorum
consisting of directors who were not parties to the action, suit, or proceeding
involved; (ii) if such a quorum is not obtainable, or even if obtainable and a
quorum of disinterested directors so directs, by independent counsel in a
written opinion; or (iii) by the shareholders, the Company is obligated to
indemnify any person who incurs liability by reason of the fact that he is or
was a director, officer, employee or agent of the Company, or is or was serving
at its request as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise, or as a
member of any committee or similar body, if he acted in good faith and in a
manner he reasonably believed to be in or not opposed to the best interests of
the Company, and with respect to any criminal action or proceeding, had no
reasonable cause to

                                      II-1


believe his conduct was unlawful. However, in an action by or in the right of
the Company, no indemnification will be made if such person shall be adjudged
to be liable to the Company, unless such indemnification is allowed by a court
of competent jurisdiction.

   The indemnification agreements referred to above provide that the Company is
obligated to indemnify the specified director or executive officer to the
fullest extent permitted by law. The agreements provide that, upon request by a
director or executive officer, the Company is obligated to advance expenses for
defense of a claim made against the director or executive officer. The
obligation of the Company to indemnify the director or executive officer is
subject to applicable law and the determination by a "reviewing party" selected
by the board of directors that the director or executive officer is entitled to
indemnification. In addition, the agreements obligate the Company to indemnify
the specified executive officer or director to the extent of the Company's
recoveries under insurance policies regardless of whether the director or
executive officer is ultimately determined to be entitled to indemnification.
The agreements also provide for partial indemnification if a portion of a claim
for indemnification is not allowed by the reviewing party appointed by the
board of directors.

   Under an insurance policy obtained by the Company, coverage of Company
officers and directors against liability for neglect, errors, omissions or
breaches of duty in their capacities as such is provided for both the Company,
to the extent that it is obligated to indemnify such officers and directors,
and the officers and directors themselves. Additional coverage is provided to
the Company for claims arising from any such conduct in connection with any
purchase or sale of, or any offer to purchase or sell, securities issued by the
Company. Such coverage is provided in the amount of $200,000,000, with a
retained limit by the Company of $250,000. The insurance company is obligated
to pay any covered loss in excess of the $250,000 retained limit and covered
defense costs from the first dollar, up to the policy limit of $200,000,000.
Among the policy exclusions are those which exclude coverage for accounting for
profits made within the meaning of Section 16(b) of the Securities Exchange Act
of 1934, claims based upon or attributable to directors and officers gaining
any personal profit or advantage to which such individuals are not legally
entitled, and for any claims brought about or attributable to the dishonesty of
an officer or director.

   It is recognized that the above-summarized provisions of the Company's by-
laws, the indemnification agreements and the applicable provisions of the
Oklahoma General Corporation Act may be sufficiently broad to indemnify
officers, directors and controlling persons of the Company against liabilities
arising under such act.

   The Company and Western Resources, Inc. ("WRI") have entered into a
Registration Rights Agreement that provides for indemnification of the
Company's directors, officers, employees and controlling persons, if any, in
any offering or sale of shares of common stock, obtainable upon conversion of
the Series A Convertible Preferred Stock or Series B Convertible Preferred
Stock, against any claims (including amounts paid in settlement), or actions or
proceedings in respect thereof, arising out of or based upon an untrue
statement or alleged untrue statement of a material fact contained in such
registration statement or prospectus contained therein, or any document
incorporated by reference therein, or arising out of or based upon any omission
or alleged omission to state therein a material fact required to be stated or
necessary to make the statements therein not misleading, in each case only to
the extent that such untrue statement or alleged untrue statement or omission
or alleged omission was made in reliance upon and in conformity with written
information furnished to the Company by WRI or an agent or underwriter thereof
expressly for use therein.

                                      II-2


Item 16. Exhibits.



 Exhibit
 Number  Description
 ------- -----------
      
  1.1*   Form of Underwriting Agreement relating to Debt Securities.

  1.2*   Form of Underwriting Agreement relating to Common Stock.

  4.1    Form of Indenture between the Company and The Chase Manhattan Bank,
         formerly known as Chase Bank of Texas, National Association, as
         Trustee (the "Trustee"), relating to the Securities (incorporated by
         reference to Exhibit 4.1 to the Company's Registration Statement on
         Form S-3 (Commission File No. 333-62279)).

  4.2    First Supplemental Indenture (incorporated by reference to Exhibit
         (5)(a) to the Company's Current Report on Form 8-K dated September 24,
         1998).

  4.3    Second Supplemental Indenture (incorporated by reference to Exhibit
         (5)(b) to the Company's Current Report on Form 8-K dated September 24,
         1998).

  4.4    Third Supplemental Indenture (incorporated by reference to Exhibit 4
         to the Company's Current Report on Form 8-K dated February 8, 1999).

  4.5    Fourth Supplemental Indenture (incorporated by reference to Exhibit
         4.5 to the Company's Registration Statement on Form S-3 (Commission
         File No. 333-76375)).

  4.6    Fifth Supplemental Indenture (incorporated by reference to Exhibit 4
         to the Company's Current Report on Form 8-K dated August 17, 1999).

  4.7    Sixth Supplemental Indenture (incorporated by reference to Exhibit
         4.11 to the Company's Registration Statement on Form S-4 (Commission
         File No. 333-32254)).

  4.8    Seventh Supplemental Indenture (incorporated by reference to Exhibit 4
         to the Company's Current Report on Form 8-K dated April 24, 2000).

  4.9+   Eighth Supplemental Indenture between the Company and the Trustee.

  4.10*  Form of Supplemental Indenture relating to Debt Securities.

  4.11   Form of Debt Security (incorporated by reference to Exhibit 4.2 to the
         Company's Registration Statement on Form S-3 (Commission File No. 333-
         62279)).

  4.12   Certificate of Incorporation of the Company, filed May 16, 1997
         (incorporated by reference to Exhibit 3.1 to the Company's
         Registration Statement on Form S-4, as amended (Commission File No.
         333-27467)).

  4.13   Certificate of Merger of the Company, filed November 26, 1997
         (incorporated by reference to Exhibit (1)(b) to the Company's
         Quarterly Report on Form 10-Q for the quarter ended May 31, 1998).

  4.14   Amended Certificate of Incorporation of the Company, filed January 16,
         1998 (incorporated by reference to Exhibit (1)(b) to the Company's
         Quarterly Report on Form 10-Q for the quarter ended May 31, 1998).

  4.15+  Amendment to Certificate of Incorporation of the Company, filed May
         23, 2001.

  4.16   By-laws of the Company, as amended (incorporated by reference to
         Exhibit (3)(d) to the Company's Annual Report on Form 10-K for the
         year ended August 31, 1999).

  4.17   Article "Fourth" of the Certificate of Incorporation of the Company
         (Preferred Stock and Common Stock) (incorporated by reference to
         Exhibit 3.1 to the Company's Registration Statement on Form
         S-4, as amended (Commission File No. 333-27467)).



                                      II-3




 Exhibit
 Number  Description
 ------- -----------
      
   4.18  Certificate of Designation for Convertible Preferred Stock of the
         Company filed November 26, 1997 (incorporated by reference from
         Exhibit 3.3 to the Company's Registration Statement on Form S-4, as
         amended (Commission File No. 333-27467)).

   4.19  Certificate of Designation for Series C Participating Preferred Stock
         of the Company, filed November 26, 1998 (incorporated by reference to
         Exhibit 1 to the Company's Registration Statement on Form
         8-A filed with the Commission on November 26, 1997).

   4.20  Form of Common Stock Certificate (incorporated by reference to Exhibit
         1 to the Company's Registration Statement on Form 8-A filed with the
         Commission on November 21, 1997).

   4.21  Rights Agreement, dated November 26, 1997, between the Company and
         Liberty Bank and Trust Company of Oklahoma City, N.A., as Rights Agent
         (incorporated by reference to Exhibit 2.3 to the Company's
         Registration Statement on Form S-4, as amended (Commission File No.
         333-27467)).

   4.22  Shareholder Agreement, dated November 26, 1997, between Western
         Resources, Inc. and the Company (incorporated by reference to Exhibit
         2.2 to the Company's Registration Statement on Form S-4, as amended
         (Commission File No. 333-27467)).

   4.23  Form of Registration Rights Agreement, dated November 26, 1997,
         between Western Resources, Inc. and the Company (incorporated by
         reference to Exhibit 3.4 to the Company's Registration Statement on
         Form S-4, as amended (Commission File No. 333-27467)).

   5.1+  Opinion of Gable & Gotwals regarding the validity of the Securities.

  12.1   Computation of Ratio of Earnings to Fixed Charges (incorporated by
         reference to Exhibit (12)(a) to the Company's report on Form 10-Q for
         the quarterly period ended March 31, 2001, to Exhibits (12)(a) and
         (12)(a.1) to the Company's Annual Report on Form 10-K for the year
         ended December 31, 2000, and to Exhibit (12)(a) to the Company's
         Annual Report on Form 10-K for the year ended August 31, 1999).

  23.1+  Consent of KPMG LLP.

  23.2   Consent of Gable & Gotwals (included in Exhibit 5.1).

  24.1   Powers of Attorney (included on the signature page hereof).

  25.1+  Statement of Eligibility of the Trustee under the Trust Indenture Act
         of 1939 on Form T-1 relating to the Indenture.

--------
*  To be filed by amendment or as an exhibit to a current report on Form 8-K.
+  Filed herewith.

Item 17. Undertakings.

   (a) The undersigned registrant hereby undertakes:

     (1) To file, during any period in which offers or sales are being made,
  a post-effective amendment to this registration statement:

       (i) To include any prospectus required by Section 10(a)(3) of the
    Securities Act of 1933;

       (ii) To reflect in the prospectus any facts or events arising after
    the effective date of the registration statement (or the most recent
    post-effective amendment thereof) which, individually or in the
    aggregate, represent a fundamental change in the information set forth
    in the registration statement. Notwithstanding the foregoing, any
    increase or decrease in volume of securities offered (if the total
    dollar value of securities offered would not exceed that which was
    registered) and any deviation from the low or high end of the estimated
    maximum offering range may be reflected in the form of prospectus filed
    with the Commission pursuant to Rule 424(b) if, in the aggregate, the

                                      II-4


    changes in volume and price represent no more than a 20% change in the
    maximum aggregate offering price set forth in the "Calculation of
    Registration Fee" table in the effective registration statement;

       (iii) To include any material information with respect to the plan
    of distribution not previously disclosed in the registration statement
    or any material change to such information in the registration
    statement;

provided, however, that paragraphs (a) (1) (i) and (a) (1) (ii) do not apply if
the registration statement is on Form S-3, Form S-8 or Form F-3, and the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed with or furnished to the
Commission by the registrant pursuant to Section 13 or 15(d) of the Securities
Exchange Act of 1934 that are incorporated by reference in the registration
statement.

     (2) That, for the purpose of determining any liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed
  to be a new registration statement relating to the securities offered
  therein, and the offering of such securities at that time shall be deemed
  to be the initial bona fide offering thereof.

     (3) To remove from registration by means of a post-effective amendment
  any of the securities being registered which remain unsold at the
  termination of the offering.

   (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to section 15(d) of the Securities Exchange Act
of 1934) that is incorporated by reference in the registration statement shall
be deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at the time shall be deemed to be
the initial bona fide offering thereof.

   (c) Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or incurred or paid by a director, officer or
controlling person of the registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the Act and
will be governed by the final adjudication of such issue.

   (d) The undersigned registrant hereby undertakes that:

     (1) For purposes of determining any liability under the Securities Act
  of 1933, the information omitted from the form of prospectus filed as part
  of this registration statement in reliance upon Rule 430A and contained in
  a form of prospectus filed by the registrant pursuant to Rule 424 (b) (1)
  or (4) or 497(h) under the Securities Act of 1933 shall be deemed to be
  part of this registration statement as of the time it was declared
  effective.

     (2) For the purpose of determining any liability under the Securities
  Act of 1933, each post-effective amendment that contains a form of
  prospectus shall be deemed to be a new registration statement relating to
  the securities offered therein, and the offering of such securities at that
  time shall be deemed to be the initial bona fide offering thereof.

                                      II-5


                                   SIGNATURES

   Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Tulsa, State of Oklahoma, on the 18th day of July,
2001.

                                          ONEOK, INC.

                                                      /s/ Jim Kneale
                                          By: _________________________________
                                                         Jim Kneale
                                              Senior Vice President, Treasurer
                                                and Chief Financial Officer

   KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
immediately below constitutes and appoints Jim Kneale and John A. Gaberino,
Jr., and each of them, his or her true and lawful attorney-in-fact and agent,
with full power of substitution and resubstitution, for him or her and in his
or her name, place and stead, in any and all capacities, to sign any and all
amendments (including post-effective amendments) to this Registration
Statement, and registration statements filed pursuant to Rule 462 under the
Securities Act of 1933, and to file the same with all exhibits thereto and
other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorney-in-fact and agents, and each of them,
full power and authority to do and perform each and every act and thing
requisite and necessary to be done, as fully to all intents and purposes as he
or she might or could do in person, hereby ratifying and confirming all that
said attorney-in-fact and agents or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

   Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated and on the 18th day of July, 2001.



              Signature                                   Title
              ---------                                   -----

                                    
         /s/ David L. Kyle             Chairman of the Board, President, Chief
______________________________________  Executive Officer and Director (Principal
            David L. Kyle               Executive Officer)

                                       Director
______________________________________
          Edwyna G. Anderson

        /s/ William M. Bell            Director
______________________________________
           William M. Bell

      /s/ Douglas R. Cummings          Director
______________________________________
         Douglas R. Cummings

        /s/ William L. Ford            Director
______________________________________
           William L. Ford

         /s/ John B. Dicus             Director
______________________________________
            John B. Dicus




                                      II-6




              Signature                                   Title
              ---------                                   -----
                                    
        /s/ Douglas T. Lake            Director
______________________________________
           Douglas T. Lake

         /s/ Bert H. Mackie            Director
______________________________________
            Bert H. Mackie

           /s/ Jim Kneale              Senior Vice President, Treasurer and Chief
______________________________________  Financial Officer (Principal Financial
              Jim Kneale                Officer)

       /s/ Douglas A. Newsom           Director
______________________________________
          Douglas A. Newsom

         /s/ Gary D. Parker            Director
______________________________________
            Gary D. Parker

                                       Director
______________________________________
             J. D. Scott

         /s/ Beverly Monnet            Vice President, Controller and Chief
______________________________________  Accounting Officer (Principal Accounting
            Beverly Monnet              Officer)


                                      II-7


                                 EXHIBIT INDEX



 Exhibit
 Number  Description
 ------- -----------
      
  1.1*   Form of Underwriting Agreement relating to Debt Securities.

  1.2*   Form of Underwriting Agreement relating to Common Stock.

  4.1    Form of Indenture between the Company and The Chase Manhattan Bank,
         formerly known as Chase Bank of Texas, National Association as Trustee
         (the "Trustee"), relating to the Securities (incorporated by reference
         to Exhibit 4.1 to the Company's Registration Statement on Form S-3
         (Commission File No. 333-62279)).

  4.2    First Supplemental Indenture (incorporated by reference to Exhibit
         (5)(a) to the Company's Current Report on Form 8-K dated September 24,
         1998).

  4.3    Second Supplemental Indenture (incorporated by reference to Exhibit
         (5)(b) to the Company's Current Report on Form 8-K dated September 24,
         1998).

  4.4    Third Supplemental Indenture (incorporated by reference to Exhibit 4
         to the Company's Current Report on Form 8-K dated February 8, 1999).

  4.5    Fourth Supplemental Indenture (incorporated by reference to Exhibit
         4.5 to the Company's Registration Statement on Form S-3 (Commission
         File No. 333-76375)).

  4.6    Fifth Supplemental Indenture (incorporated by reference to Exhibit 4
         to the Company's Current Report on Form 8-K dated August 17, 1999).

  4.7    Sixth Supplemental Indenture (incorporated by reference to Exhibit
         4.11 to the Company's Registration Statement on Form S-4 (Commission
         File No. 333-32254)).

  4.8    Seventh Supplemental Indenture (incorporated by reference to Exhibit 4
         to the Company's Current Report on Form 8-K dated April 24, 2000).

  4.9+   Eighth Supplemental Indenture between the Company and the Trustee.

  4.10*  Form of Supplemental Indenture relating to Debt Securities.

  4.11   Form of Debt Security (incorporated by reference to Exhibit 4.2 to the
         Company's Registration Statement on Form S-3 (Commission File No. 333-
         62279)).

  4.12   Certificate of Incorporation of the Company, filed May 16, 1997
         (incorporated by reference to Exhibit 3.1 to the Company's
         Registration Statement on Form S-4, as amended (Commission File
         No. 333-27467)).

  4.13   Certificate of Merger of the Company, filed November 26, 1997
         (incorporated by reference to Exhibit (1)(b) to the Company's
         Quarterly Report on Form 10-Q for the quarter ended May 31, 1998).

  4.14   Amended Certificate of Incorporation of the Company, filed January 16,
         1998 (incorporated by reference to Exhibit (1)(b) to the Company's
         Quarterly Report on Form 10-Q for the quarter ended May 31, 1998).

  4.15+  Amendment to Certificate of Incorporation of the Company, filed May
         23, 2001.

  4.16   By-laws of the Company, as amended (incorporated by reference to
         Exhibit (3)(d) to the Company's Annual Report on Form 10-K for the
         year ended August 31, 1999).

  4.17   Article "Fourth" of the Certificate of Incorporation of the Company
         (Preferred Stock and Common Stock) (incorporated by reference to
         Exhibit 3.1 to the Company's Registration Statement on
         Form S-4, as amended (Commission File No. 333-27467)).



                                      II-8




 Exhibit
 Number  Description
 ------- -----------
      
  4.18   Certificate of Designation for Convertible Preferred Stock of the
         Company filed November 26, 1997 (incorporated by reference from
         Exhibit 3.3 to the Company's Registration Statement on Form S-4, as
         amended (Commission File No. 333-27467)).

  4.19   Certificate of Designation for Series C Participating Preferred Stock
         of the Company, filed
         November 26, 1998 (incorporated by reference to Exhibit 1 to the
         Company's Registration Statement on Form 8-A filed with the Commission
         on November 26, 1997).

  4.20   Form of Common Stock Certificate (incorporated by reference to Exhibit
         1 to the Company's Registration Statement on Form 8-A filed with the
         Commission on November 21, 1997).

  4.21   Rights Agreement, dated November 26, 1997, between the Company and
         Liberty Bank and Trust Company of Oklahoma City, N.A., as Rights Agent
         (incorporated by reference to Exhibit 2.3 to the Company's
         Registration Statement on Form S-4, as amended (Commission File No.
         333-27467)).

  4.22   Shareholder Agreement, dated November 26, 1997, between Western
         Resources, Inc. and the Company (incorporated by reference to Exhibit
         2.2 to the Company's Registration Statement on
         Form S-4, as amended (Commission File No. 333-27467)).

  4.23   Form of Registration Rights Agreement, dated November 26, 1997,
         between Western Resources, Inc. and the Company (incorporated by
         reference to Exhibit 3.4 to the Company's Registration Statement on
         Form S-4, as amended (Commission File No. 333-27467)).

  5.1+   Opinion of Gable & Gotwals regarding the validity of the Securities.

 12.1    Computation of Ratio of Earnings to Fixed Charges (incorporated by
         reference to Exhibit (12)(a) to the Company's report on Form 10-Q for
         the quarterly period ended March 31, 2001, to Exhibits (12)(a) and
         (12)(a.1) to the Company's Annual Report on Form 10-K for the year
         ended December 31, 2000, and to Exhibit (12)(a) to the Company's
         Annual Report on Form 10-K for the year ended August 31, 1999).

 23.1+   Consent of KPMG LLP.

 23.2    Consent of Gable & Gotwals (included in Exhibit 5.1).

 24.1    Powers of Attorney (included in the signature page of this
         Registration Statement).

 25.1+   Statement of Eligibility of the Trustee under the Trust Indenture Act
         of 1939 on Form T-1 relating to the Indenture.

--------
*  To be filed by amendment or as an exhibit to a current report on Form 8-K.
+  Filed herewith.

                                      II-9