Marathon Oil (MRO)

TAX SHARING AGREEMENT

This TAX SHARING AGREEMENT is entered into as of December 31, 2001, by and among USX Corporation (“USX”) (to be renamed Marathon Oil Corporation), a Delaware corporation (together with its successors, “Marathon”) and United States Steel LLC (to be converted into a corporation named United States Steel Corporation), a Delaware limited liability company (together with its successors, “United States Steel”).

TAX SHARING AGREEMENT

This TAX SHARING AGREEMENT is entered into as of December 31, 2001, by and among USX Corporation (“USX”) (to be renamed Marathon Oil
Corporation), a Delaware corporation (together with its successors, “Marathon”) and United States Steel LLC (to be converted into a corporation named United States Steel Corporation), a Delaware limited liability company (together with its
successors, “United States Steel”).

Tax Sharing Agreement

        Marathon and United States Steel have a tax sharing agreement that applies to each of their consolidated tax reporting groups. During 2006, the Internal Revenue Service completed its review of all federal income tax returns filed by USX Corporation for taxable periods ending on or prior to the date of the Separation. Marathon and United States Steel have settled all matters related to federal income taxes under this agreement. Remaining matters related to state and local income taxes are not expected to have any significant effect on Marathon.

Tax Sharing Agreement

        Marathon and United States Steel have a tax sharing agreement that applies to each of their consolidated tax reporting groups. Provisions of this agreement include the following:

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for any taxable period, or any portion of any taxable period, ended on or before December 31, 2001, unpaid tax sharing payments will be made between Marathon and United States Steel generally in accordance with the general tax sharing principles in effect before the Separation;

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no tax sharing payments will be made with respect to taxable periods, or portions thereof, beginning after December 31, 2001; and



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provisions relating to the tax and related liabilities, if any, that result from the Separation ceasing to qualify as a tax-free transaction and limitations on post-Separation activities that might jeopardize the tax-free status of the Separation.

        Under the general tax sharing principles in effect before the Separation:

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the taxes payable by each of the Marathon Group and the U.S. Steel Group were determined as if each of them had filed its own consolidated, combined or unitary tax return; and



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the U.S. Steel Group would receive the benefit, in the form of tax sharing payments by the parent corporation, of the tax attributes, consisting principally of net operating losses and various credits, that its business generated and the parent used on a consolidated basis to reduce its taxes otherwise payable.

        In accordance with the tax sharing agreement, at the time of the Separation, Marathon made a preliminary settlement with United States Steel of approximately $440 million as the net tax sharing payments owed to it for the year ended December 31, 2001 under the pre-Separation tax sharing principles.

        The tax sharing agreement also addresses the handling of tax audits and contests and other matters respecting taxable periods, or portions of taxable periods, ended before December 31, 2001.

        In the tax sharing agreement, each of Marathon and United States Steel promised the other party that it:

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would not, before January 1, 2004, take various actions or enter into various transactions that might, under section 355 of the Internal Revenue Code of 1986, jeopardize the tax-free status of the Separation; and



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would be responsible for, and indemnify and hold the other party harmless from and against, any tax and related liability, such as interest and penalties, that results from the Separation ceasing to qualify as tax-free because of its taking of any such action or entering into any such transaction.

        The prescribed actions and transactions include:

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the liquidation of Marathon or United States Steel; and



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the sale by Marathon or United States Steel of its assets, except in the ordinary course of business.

        In case a taxing authority seeks to collect a tax liability from one party that the tax sharing agreement has allocated to the other party, the other party has agreed in the sharing agreement to indemnify the first party against that liability.

        Even if the Separation otherwise qualified for tax-free treatment under section 355 of the Internal Revenue Code, the Separation may become taxable to Marathon under section 355(e) of the Internal Revenue Code if capital stock representing a 50 percent or greater interest in either Marathon or United States Steel is acquired, directly or indirectly, as part of a plan or series of related transactions that include the Separation. For this purpose, a "50 percent or greater interest" means capital stock possessing at least 50 percent of the total combined voting power of all classes of stock entitled to vote or at least 50 percent of the total value of shares of all classes of capital stock. To minimize this risk, both Marathon and United States Steel agreed in the tax sharing agreement that they would not enter into any transactions or make any change in their equity structures that could cause the Separation to be treated as part of a plan or series of related transactions to which those provisions of section 355(e) of the Internal Revenue Code may apply. If an acquisition occurs that results in the Separation being taxable under section 355(e) of the Internal Revenue Code, the agreement provides that the resulting corporate tax liability will be borne by the party involved in that acquisition transaction.

        Although the tax sharing agreement allocates tax liabilities relating to taxable periods ending on or prior to the Separation, each of Marathon and United States Steel, as members of the same consolidated tax reporting group during any portion of a taxable period ended on or prior to the date of the Separation, is jointly and severally liable under the Internal Revenue Code for the federal income tax liability of the entire consolidated tax reporting group for that year. To address the possibility that the taxing authorities may seek to collect all or part of a tax liability from one party where the tax sharing agreement allocates that liability to the other party, the agreement includes indemnification provisions that would entitle the party from whom the taxing authorities are seeking collection to obtain indemnification from the other party, to the extent the agreement allocates that liability to that other party. Marathon can provide no assurance, however, that United States Steel will be able to meet its indemnification obligations, if any, to Marathon that may arise under the tax sharing agreement.

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