X0306 4 2013-01-02 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 2012-12-11 5 G 0 E 2991 0.00 D 73330.9094 D Marathon Oil Corporation Common Stock 2012-12-11 5 G 0 E 2991 0.00 A 2991 I By Spouse's Trust Marathon Oil Corporation Common Stock 2013-01-02 4 A 0 5529.226 0.00 A 78860.1354 D The reporting person transferred 2,991 shares to his spouse as a gift. The reporting person's spouse simultaneously transferred the 2,991 shares to her irrevocable defective grantor trust ("Spouse's Trust") as a gift. The reporting person is the trustee of the Spouse's Trust and the reporting person's spouse is the settlor of the Spouse's Trust. The beneficiaries under the Spouse's Trust are the children of the reporting person and spouse. Non-Retainer Annual Director Stock Unit Award granted under Marathon Oil Corporation 2012 Incentive Compensation Plan. The annual non-retainer stock based compensation represented by these common stock units are credited to an unfunded account. These common stock units, along with their accrued dividend equivalent rights, will vest on January 2, 2016 and be payable in shares of common stock. Includes dividends of 1,772.9086 shares previously not reported pursuant to Rule 16a-11. Yvonne R. Kunetka, Attorney-in-Fact for Philip Lader 2013-01-04