===============================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                 --------------
                                   Form 10-Q/A
                                (Amendment No. 3)
                                 --------------

     [X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                             EXCHANGE ACT OF 1934

                  For the quarterly period ended June 30, 2004

                                       OR

     [ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                            EXCHANGE ACT OF 1934

             For the transition period from__________ to __________

                         Commission file number: 1-12091

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

                            MILLENNIUM CHEMICALS INC.
             (Exact name of registrant as specified in its charter)

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

           Delaware                                22-3436215
(State or other jurisdiction of          (I.R.S. Employer Identification No.)
incorporation or organization)

                           20 Wight Avenue, Suite 100
                              Hunt Valley, MD 21030
                    (Address of principal executive offices)

                                  410-229-4400
              (Registrant's telephone number, including area code)

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

       Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant is required to file such reports) and (2) has been subject to such
filing requirements for the past 90 days. Yes [X] No [ ].

       Indicate by check mark whether the registrant is an accelerated filer
as defined in Rule 12b-2 of the Act).

Yes [X] No [ ].

       Indicate the number of shares outstanding of each of the issuer's classes
of common stock, as of the latest practicable date: 65,379,892 shares of Common
Stock, par value $.01 per share, as of July 31, 2004, excluding 12,516,694
shares held by the registrant, its subsidiaries and certain Company trusts that
are not entitled to vote.

===============================================================================












Explanatory Note

Millennium Chemicals Inc. (the "Company") filed Amendment No. 2
("Amendment No. 2") to its Quarterly Report on Form 10-Q for the period ended
June 30, 2004 (the "Quarterly Report") to provide additional information
relating to the Company's material weakness in internal control over financial
reporting relating to the computation of deferred income taxes for the Company's
investment in Equistar Chemicals, LP; the analysis and re-computation performed
by the Company to correct such deferred income tax calculation; and the steps
the Company is taking to remediate such material weakness.

This Amendment No. 3 to the Quarterly Report ("Amendment No. 3") contains
the text of Amendment No. 2 in its entirety apart from the explanatory note and
exhibits thereto. This Amendment No. 3 also includes as exhibits certificates of
each of the Chief Executive Officer and Chief Financial Officer that include
paragraphs 4 and 5, which were unintentionally omitted from the certificates
filed as exhibits to Amendment No. 2.

                          PART I. FINANCIAL INFORMATION

Item 4. Controls and Procedures

(a)  The Company maintains disclosure controls and procedures that are designed
     to provide reasonable assurance that information required to be disclosed
     in the Company's filings under the Securities Exchange Act of 1934 is
     recorded, processed, summarized and reported within the periods specified
     in the rules and forms of the Securities and Exchange Commission
     (the "SEC") and that such information is accumulated and communicated
     to the Company's management, including its principal executive officer
     and principal financial officer, as appropriate, to allow timely
     decisions regarding required disclosure.

     As a result of tax integration activities that began in the second quarter
     of 2004 with respect to the Company's proposed business combination with
     Lyondell, the Company determined at the beginning of July 2004 that it had
     made errors in the computation of its tax basis in Equistar, which in turn
     had been used to compute the Company's deferred income taxes. In response
     to the determination that errors had been made, the Company performed a
     thorough analysis and re-computation of the Company's tax basis in
     Equistar. In late July 2004, the Company completed the analysis and
     re-computation necessary to verify and quantify the errors and prepare a
     restatement to correct the errors, which restatement was reflected in
     Amendment No. 2 to the Company's Annual Report on Form 10-K for the fiscal
     year ended December 31, 2003, filed with the SEC on August 9, 2004,
     Amendment No. 1 to the Company's Quarterly Report on Form 10-Q for the
     period ended March 31, 2004, and the Company's Quarterly Report on
     Form 10-Q for the quarterly period ended June 30, 2004 ("June 10-Q"), filed
     with the SEC on August 9, 2004.

     The restatement of prior periods' financial statements that resulted from
     the analysis and recomputation discussed above decreased the Company's
     liability for deferred income taxes and shareholders' deficit at June 30,
     2004, March 31, 2004, and December 31, 2003 and 2002 by $15 million.
     The restatement similarly decreased liabilities for deferred income taxes
     and increased shareholders' equity at December 31, 2001 and 2000 by
     $15 million. The restatement did not affect the Company's cash flow or
     operating income in any period.

     The errors corrected in the restatement were the result of (i) an incorrect
     computation by the Company in 1998 of the Company's original tax basis in
     the net assets it contributed to Equistar upon the joint venture's
     formation in December 1997 and (ii) incorrect computations by the Company
     for 1998 and 1999 of changes in the amount of such tax basis. The Company
     also discovered a de minimis error made in 2001. The Company believes that
     the errors were attributable to a material weakness in internal control
     over financial reporting relating to the computation by the Company of
     deferred income taxes for the Company's investment in Equistar. The
     material weakness consisted of (i) inadequate review and verification by
     the Company in 1998 of tax basis data relating to net assets contributed
     by the Company to Equistar in December 1997, and (ii) incorrect
     interpretation by the Company of Equistar tax return information provided
     by the "tax matters partner" of Equistar and used by Millennium to compute
     changes in its tax basis in Equistar for 1998 and 1999. Under Equistar's
     partnership agreement, Lyondell serves as the tax matters partner and, as
     such, prepares and files Equistar's tax returns.

     In order to remediate the material weakness in internal control over
     financial reporting, the Company is documenting the procedures used to
     analyze and re-compute the Company's tax basis in Equistar in July 2004
     for









     implementation with respect to the third quarter of 2004 and subsequent
     reporting periods. These procedures include (i) the detailed review by the
     Company's Director-Tax and its Vice President-Tax of estimates of tax
     return data provided quarterly by Equistar's tax matters partner, (ii)
     followed by discussions of the results of such review with the tax matters
     partner to confirm the correctness of the Company's interpretation of the
     estimated tax return data provided by the tax matters partner and (iii)
     thereafter, review of the results of these procedures by the Company's
     Corporate Controller and Chief Financial Officer. Although these procedures
     will be implemented for the third quarter of 2004, the material weakness
     will not be considered remediated until these procedures operate for a
     period of time, are tested and it is concluded that such procedures are
     operating effectively.

     The Company completed in early August 2004, prior to filing the June 10-Q,
     an evaluation under the supervision and with the participation of the
     Company's management, including the Company's principal executive officer
     and principal financial officer, of the effectiveness of the design and
     operation of the Company's disclosure controls and procedures as of June
     30, 2004. Based on this evaluation, the Company's principal executive
     officer and principal financial officer concluded that, solely as a result
     of the material weakness referred to above, the Company's disclosure
     controls and procedures were not effective at the reasonable assurance
     level as of June 30, 2004. However, as a result of the analysis and
     re-computation discussed above, management believes that the financial
     statements included in the June 10-Q fairly present in all material
     respects the Company's financial condition, results of operations and cash
     flows for the fiscal periods presented.

(b)  There were no changes in the Company's internal control over financial
     reporting that occurred during the most recent fiscal quarter covered by
     this Quarterly Report that have materially affected, or are reasonably
     likely to materially affect, the Company's internal control over financial
     reporting.

     As a result of Section 404 of the Sarbanes-Oxley Act of 2002 and the rules
     issued thereunder (the "Section 404 Requirements"), the Company will be
     required to include in its Annual Report on Form 10-K for the year ending
     December 31, 2004 a report on management's assessment of the effectiveness
     of the Company's internal control over financial reporting. As part of the
     process of preparing for compliance with the Section 404 Requirements, in
     2003, the Company initiated a review of its internal control over
     financial reporting. This review is being conducted under the direction of
     senior management. As a result, management has made improvements to the
     Company's internal control through the date of the filing of this
     Amendment No. 2 as part of its normal review process. The Company's
     management does not believe these changes have materially affected, or are
     reasonably likely to materially affect, the Company's internal control
     over financial reporting. The Company anticipates that improvements will
     continue to be made as part of the ongoing review.

Item 6. Exhibits and Reports on Form 8-K

(a)     Exhibits -

        10.1   Fifth Amendment dated as of July 7, 2004 to the Credit Agreement
               dated as of June 18, 2001 among Millennium America Inc., as
               Borrower, Millennium Inorganic Chemicals Limited, as Borrower,
               certain borrowing subsidiaries of Millennium Chemicals Inc. from
               time to time party thereto, Millennium Chemicals Inc., as
               Guarantor, the lenders from time to time party thereto, Bank of
               America, N.A., as Syndication Agent and JP Morgan Chase Bank, as
               Administrative Agent and as Collateral Agent.*








        31.1   Certificate of Principal Executive Officer pursuant to Section
               302 of the Sarbanes-Oxley Act of 2002.**

        31.2   Certificate of Principal Financial Officer pursuant to Section
               302 of the Sarbanes-Oxley Act of 2002.**

        32.1   Certificate of Principal Executive Officer pursuant to Section
               906 of the Sarbanes-Oxley Act of 2002 (Furnished, not filed, in
               accordance with Item 601(b)(32)(ii) of Regulation S-K, 17 CFR
               229.601(b)(32)(ii)).*

        32.2   Certificate of Principal Financial Officer pursuant to Section
               906 of the Sarbanes-Oxley Act of 2002 (Furnished, not filed, in
               accordance with Item 601(b)(32)(ii) of Regulation S-K, 17 CFR
               229.601(b)(32)(ii)).*




     * Filed or furnished with Amendment No. 1 to the Company's Quarterly Report
on Form 10-Q for the quarter ended June 30, 2004.

    ** Filed or furnished herewith.

(b) Reports on Form 8-K.

Current Reports on Form 8-K dated May 17, 2004, May 18, 2004, July 29, 2004 and
August 9, 2004 were filed or furnished during the quarter ended June 30, 2004
and through the date hereof. Such Current Reports either filed or furnished
information to the Securities and Exchange Commission.

                                    SIGNATURE

       Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.



                                      MILLENNIUM CHEMICALS INC.

Date: September 24, 2004              By:        /s/ JOHN E. LUSHEFSKI
                                          -----------------------------------
                                                   John E. Lushefski
                                               Executive Vice President
                                              and Chief Financial Officer
                                           (as duly authorized officer and
                                             principal financial officer)











                                  Exhibit Index




Exhibit
 Number                         Description of Document

        
  31.1    Certificate of Principal Executive Officer pursuant to Section 302 of
          the Sarbanes-Oxley Act of 2002.

  31.2    Certificate of Principal Financial Officer pursuant to Section 302 of
          the Sarbanes-Oxley Act of 2002.