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 OF SECURITIES 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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(Print or Type Responses)

1. Name and Address of Reporting Person * CAZALOT CLARENCE P JR   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 __X__ Officer (give title below) _____ Other (specify below) President and CEO (Last) (First) (Middle) C/O MARATHON OIL CORPORATION, 5555 SAN FELIPE ROAD 3. Date of Earliest Transaction (Month/Day/Year) 03/04/2011 (Street) HOUSTON, TX 77056 4. If Amendment, Date Original Filed(Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 03/04/2011   M   520,000 A $ 12.7575 1,083,742 D   Marathon Oil Corporation Common Stock 03/04/2011   S   269,712 D $ 51.614 (1) 814,030 D   Marathon Oil Corporation Common Stock               51,086 I Grantor Retained Annuity Trust (Spouse) (2) Marathon Oil Corporation Common Stock               63,448 I By Grantor Retained Annuity Trust (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Employee Stock Option (Right to Buy)

$ 12.7575

03/04/2011

M

520,000

05/28/2004(4)

05/28/2013

Common Stock

520,000

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
CAZALOT CLARENCE P JR C/O MARATHON OIL CORPORATION 5555 SAN FELIPE ROAD HOUSTON, TX 77056	X		President and CEO

Signatures

R. J. Kolencik, Attorney-in-Fact for Clarence P. Cazalot, Jr.		03/08/2011
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $51.45 to $51.83, inclusive. The reporting person has provided to the issuer, and will provide to any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (1) to this Form 4.
(2)	These shares are held by the reporting person's spouse, as trustee of a grantor retained annuity trust, for the benefit of the reporting person's spouse and her three adult children.
(3)	These shares are held by the reporting person, as trustee of a grantor retained annuity trust, for the benefit of himself and his three adult children.
(4)	Vested in cumulative annual installments of 233,333, 233,333 and 233,334 shares on May 28, 2004, 2005 and 2006, respectively.

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