Sec Form 4 Filing - USHER THOMAS J @ MARATHON OIL CORP - 2011-06-30

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person USHER THOMAS J 2. Issuer Name and Ticker or Trading Symbol MARATHON OIL CORP [ MRO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O MARATHON OIL CORPORATION, 5555 SAN FELIPE ROAD 3. Date of Earliest Transaction (MM/DD/YY) 06/30/2011 (Street) HOUSTON, TX77056 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Marathon Oil Corporation Common Stock 06/30/2011 J( 1 ) 14,470.527 ( 1 ) ( 2 ) D $ 0 ( 1 ) 1,362 D Marathon Oil Corporation Common Stock 22,018 I Revocable Trust ( 3 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other USHER THOMAS J C/O MARATHON OIL CORPORATION 5555 SAN FELIPE ROAD HOUSTON, TX77056 X Signatures R. J. Kolencik, Attorney-in-Fact for Thomas J. Usher 07/01/2011 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Effective immediately after the spin-off on June 30, 2011, of Marathon Petroleum Corporation ("MPC") by Marathon Oil Corporation ("MRO"), the reporting person ceased to be a director of Marathon Oil Corporation and became a director of Marathon Petroleum Corporation. In connection with the spin-off, MRO director restricted stock unit awards of nonemployee directors who became directors of MPC immediately after the spin-off were replaced with substitute MPC director restricted stock unit awards, each of which generally preserve the value of the original awards. ( 2 )Includes dividends of 71.636 shares previously not reported pursuant to Rule 16a-11. ( 3 )Revocable Trust Account governed by the Revocable Trust Agreement, dated July 3, 2001, pursuant to which the reporting person is the settlor, co-trustee with his spouse and beneficial owner of the shares held in said account.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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