Marathon Increases Western Oil Sands Exchangeable Share Ratio

Marathon, on Oct. 31, 2007, said that the Company's board of directors declared a dividend of 24 cents per share on Marathon Oil Corporation's common stock. The dividend is payable Dec. 10, 2007 to stockholders of record Nov. 21, 2007.

In connection with Marathon's acquisition of Western Oil Sands Inc. and the terms of the provisions applicable to the exchangeable shares, the ratio at which exchangeable shares may be exchanged for shares of Marathon common stock is subject to adjustment to account for cash dividends paid on Marathon common stock that are not matched by dividends paid to holders of the exchangeable shares.

For former shareholders of Western Oil Sands Inc. who hold exchangeable shares, the new exchange ratio is 1.00423. The new exchange ratio will take effect on Dec. 10, 2007 and will remain in effect until the next payment of a cash dividend.

The New Exchange Ratio is calculated as follows:

Opening Exchange Ratio 1.00000

Increase in Exchange Ratio* 0.00423

New Exchange Ratio 1.00423

Effective Date of the New December 10, 2007

Exchange Ratio

* The increase in the Exchange Ratio is calculated by multiplying the Marathon dividend per share of common stock by the Opening Exchange Ratio and dividing by the five day weighted average trading price of MRO common stock on the date that is three business days prior to the Marathon dividend record date.