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Washington, D.C. 20549


Under the Securities Exchange Act of 1934
(Amendment No.   )*

International Steel Group, Inc.

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)


(Cusip Number)

December 17, 2003

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

        o Rule 13d-1 (b)

        o Rule 13d-1 (c)

        x Rule 13d-1 (d)

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the notes).



CUSIP No. 460377104 Page 1 of 4

  1. Name of Reporting Person:
Cleveland-Cliffs Inc
I.R.S. Identification Nos. of above persons (entities only):

  2. Check the Appropriate Box if a Member of a Group:
    (a) o  
    (b) o  

  3. SEC Use Only:

  4. Citizenship or Place of Organization:

Number of
Owned by
Each Reporting
Person With
5. Sole Voting Power:

6. Shared Voting Power:

7. Sole Dispositive Power:

8.Shared Dispositive Power:

  9.Aggregate Amount Beneficially Owned by Each Reporting Person:

  10.Check if the Aggregate Amount in Row (9) Excludes Certain Shares:

  11.Percent of Class Represented by Amount in Row (9):

  12.Type of Reporting Person:

* See Item 4 of this filing.



CUSIP No. 460377104   Page 2 of 4 Pages
Item 1(a).
  Name of Issuer: International Steel Group, Inc.
Item 1(b).
  Address of Issuer’s Principal Executive Offices:
  3250 Interstate Drive, Richfield, Ohio 44286
Item 2(a).
  Name of Person Filing: Cleveland-Cliffs Inc
Item 2(b).
  Address of Principal Business Office, or, if None, Residence:
  1100 Superior Avenue, Cleveland, Ohio 44114
Item 2(c).
  Citizenship: Ohio Corporation
Item 2(d).
  Title of Class of Securities: Common Stock, par value $0.01 per share
Item 2(e).
  CUSIP Number: 460377104

Item 3. If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a:

  [  ]   Broker or dealer registered under Section 15 of the Exchange Act;
  [  ]   Bank as defined in Section 3(a)(6) of the Exchange Act;
  [  ]   Insurance company as defined in Section 3(a)(19) of the Exchange Act;
  [  ]   Investment company registered under Section 8 of the Investment Company Act;
  [  ]   An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);
  [  ]   An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);
  [  ]   A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
  [  ]   A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;
  [  ]   A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act;
  [  ]   Group, in accordance with Rule 13d-1(b)(1)(ii)(J).



CUSIP No. 460377104   Page 3 of 4 Pages

Item 4. Ownership.

     Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

  Amount beneficially owned: 5,856,571*
  Percent of class: 6.0%
  Number of shares as to which the person has:
  (i)   Sole power to vote or direct the vote   5,049,900*
  (ii)   Shared power to vote or direct the vote   806,671*
  (iii)   Sole power to dispose or to direct the disposition of   5,049,900*
  (iv)   Shared power to dispose or to direct the disposition of   806,671*

* Cleveland-Cliffs Inc (“Cleveland-Cliffs”) is an affiliate of Cleveland-Cliffs Inc and Associated Companies Collective Investment Trust (“Trust”). The Trust is the holder of record of 806,671 shares of International Steel Group, Inc.’s common stock. By reason of such relationship, Cleveland-Cliffs may be deemed to share dispositive power or investment control over the shares owned by the Trust. However, Cleveland-Cliffs does not have the right to receive dividends from, or the proceeds from the sale of, the shares held by the Trust and disclaims beneficial ownership of such shares.

Item 5. Ownership of Five Percent or Less of a Class.

     If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [  ].

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

     Not applicable



CUSIP No. 460377104   Page 4 of 4 Pages

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

     Not applicable

Item 8. Identification and Classification of Members of the Group.

     Not applicable

Item 9. Notice of Dissolution of Group.

     Not applicable

Item 10. Certifications.

     By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.


     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

  By:   /s/ Donald J. Gallagher
      Name:   Donald J. Gallagher
      Title:   Senior Vice President, Chief
          Financial Officer and Treasurer
Dated: July 6, 2004