Marathon Oil (MRO)

Industrial Revenue Bonds

1.1 Assumption of Industrial Revenue Bond Obligations. Parent is the obligor on $479,490,000 of obligations pursuant to agreements with respect to an equal principal amount of tax exempt environmental revenue bonds issued by various governmental issuers all of which are more particularly described on Schedule 1.1 attached hereto (collectively, the “Industrial Revenue Bonds”).

(a) For a term beginning on the date hereof and ending on the earlier of the tenth anniversary of the Separation Effective Time (as defined in the Separation Agreement) or December 31, 2040, Parent hereby assigns to Steel and Steel assumes all of Parent’s rights and obligations with respect to the Industrial Revenue Bonds including, without limitation, the obligation to pay debt service on the Industrial Revenue Bonds. The term “debt service” is meant to include all sums due with respect to the Industrial Revenue Bonds including, without limitation, payments of principal, interest and premium, letter of credit fees and expenses (incurred by either Parent or Steel or both), trustee fees and expenses, issuer fees and expenses and remarketing fees and expenses.

(b) During the term of this Agreement, Steel shall provide all notices and take such other actions as may be necessary or appropriate in connection with ongoing obligations related to the Industrial Revenue Bonds.

Steel’s obligations with respect to the Industrial Revenue Bonds shall include payment of amounts due upon any defaults or acceleration of any of the obligations with respect to the Industrial Revenue Bonds other than defaults caused by Parent.

1.2 Rights of Steel. During the term of this Agreement, Steel shall have the right to exercise all of the existing contractual rights of Parent concerning the Industrial Revenue Bonds including all rights to the selection of interest rates, making prepayments or granting or releasing security interests and Parent shall use commercially reasonable efforts to assist Steel in its exercise of such rights. Notwithstanding the foregoing, Steel shall have no right to increase the principal amount or to change the maturity of any of the Industrial Revenue Bonds without the prior written consent of Parent except as set forth in Section 1.4(b).

1.3 Variable Rate Industrial Revenue Bonds. The Industrial Revenue Bonds that are designated on Schedule 1.1 as variable rate environmental revenue bonds are referred to as the “Variable Rate Bonds.” During the term of this Agreement Steel may from time to time direct conversion of the Variable Rate Bonds to different interest rate periods, and Parent shall undertake all reasonable efforts to effectuate each such conversion. Parent will not, without the prior written consent of Steel, convert any of the

Page 2

Variable Rate Bonds to a different interest rate. Notwithstanding anything in this Agreement to the contrary, Steel’s ability to direct conversion of the Variable Rate Bonds to a different interest rate period and maintain a given interest rate period shall be subject to Parent’s ability to maintain appropriate letters of credit respecting the Variable Rate Bonds. Parent shall undertake commercially reasonable efforts to obtain and maintain letters of credit and/or such other liquidity facilities (each, a “Liquidity Facility”) as may be permitted by the applicable Bond Documents (hereinafter defined). If Parent’s ability to obtain and maintain Liquidity Facilities is reduced so that Parent’s business is adversely affected in a material way, Parent may, following timely written notice to Steel, decline to renew one or more Liquidity Facilities with respect to one or more issues of Variable Rate Bonds. Concurrently with said notice Parent shall supply an opinion of an independent third party regarding the availability of Liquidity Facilities to Parent. Steel may at any time provide substitute Liquidity Facilities applicable to one or more issues of the Variable Rate Bonds.

1.4 Refinancing

(a) If Steel notifies Parent in writing that Steel elects to redeem all or part of any of the Industrial Revenue Bonds and supplies adequate funds therefor, Parent shall reasonably assist Steel to effectuate such redemption(s) and Steel’s obligations under this Agreement shall be reduced accordingly. Parent shall not, without the prior written consent of Steel, direct the redemption of any Industrial Revenue Bonds prior to maturity.

(b) If Steel elects to refinance all or part of any of the Industrial Revenue Bonds through a tax-exempt refunding or otherwise, Parent shall take all such reasonable action as may be necessary or appropriate to reasonably assist Steel in completing the transactions contemplated by each such refinancing, so long as after the completion of such transactions, Parent does not have any obligations with respect to any new debt issued as a result. Steel agrees to undertake commercially reasonable efforts to effect such refinancings before the end of the term described in Section 1.5 hereof.

1.5 Release by Parent at end of Term. On the earlier of the tenth anniversary of the Separation Effective Time (as defined in the Separation Agreement) or December 31, 2040 Steel shall pay to Parent an amount equal to the principal amount of, all accrued and unpaid debt service then outstanding on, and any premium required to immediately retire each Industrial Revenue Bond. Upon such payment Parent shall retire all the then outstanding Industrial Revenue Bonds.