X0303 4 2011-06-30 0 0000101778 MARATHON OIL CORP MRO 0001237640 LADER PHILIP C/O MARATHON OIL CORPORATION 5555 SAN FELIPE ROAD HOUSTON TX 77056 1 0 0 0 Marathon Oil Corporation Common Stock 2011-06-30 4 J 0 22811.551 0.00 A 65922.4554 D Marathon Oil Corporation Common Stock 2011-07-01 4 A 0 1138.088 0.00 A 67060.5434 D In connection with the spin-off of Marathon Petroleum Corporation on June 30, 2011 by Marathon Oil Corporation ("MRO"), MRO director restricted common stock unit awards of nonemployee directors, who continued to serve as directors of MRO immediately after the spin-off, were replaced with adjusted MRO director restricted common stock unit awards, each of which generally preserve the value of the original awards. Non-Retainer Quarterly Director Stock Unit Award granted under Marathon Oil Corporation 2007 Incentive Compensation Plan. The quarterly non-retainer stock-based compensation represented by these common stock units are credited to an unfunded account and are payable in shares of common stock upon the reporting person's departure from the Board of Directors. Includes dividends of 213.3976 shares previously not reported pursuant to Rule 16a-11. Yvonne R. Kunetka, Attorney-in-Fact for Philip Lader 2011-07-05