SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Thill Howard J SR (Last) (First) (Middle) C/O MARATHON OIL CORPORATION 5555 SAN FELIPE ROAD (Street) HOUSTON TX 77056 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol MARATHON OIL CORP [ MRO ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) V.P.-Investor Rel./Public Aff.
	3. Date of Earliest Transaction (Month/Day/Year) 06/30/2011
	4. If Amendment, Date of 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

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	06/30/2011		J(1)		4,353	A	$0.00	17,385.6052(2)	D

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 Securities Underlying Derivative Security (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: 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)	$25.835	06/30/2011		J(3)			2,134	06/10/2006(4)	06/10/2015	Common Stock	2,134	$0.00	0	D
Employee Stock Option (Right to Buy)	$16.19	06/30/2011		J(3)		2,031		06/10/2008	06/10/2015	Common Stock	2,031	$0.00	2,031	D
Employee Stock Option (Right to Buy)	$37.818	06/30/2011		J(3)			4,268	06/01/2007(5)	06/01/2016	Common Stock	4,268	$0.00	0	D
Employee Stock Option (Right to Buy)	$23.69	06/30/2011		J(3)		4,062		06/01/2009	06/01/2016	Common Stock	4,062	$0.00	4,062	D
Employee Stock Option (Right to Buy)	$61.05	06/30/2011		J(3)			9,000	05/30/2008(6)	05/30/2017	Common Stock	9,000	$0.00	0	D
Employee Stock Option (Right to Buy)	$38.25	06/30/2011		J(3)		8,568		05/30/2010	05/30/2017	Common Stock	8,568	$0.00	8,568	D
Employee Stock Option (Right to Buy)	$54.36	06/30/2011		J(3)			7,300	02/27/2009(7)	02/27/2018	Common Stock	7,300	$0.00	0	D
Employee Stock Option (Right to Buy)	$34.06	06/30/2011		J(3)		6,944		02/27/2011	02/27/2018	Common Stock	6,944	$0.00	6,944	D
Employee Stock Option (Right to Buy)	$23.82	06/30/2011		J(3)(8)			15,300	02/25/2010(9)	02/25/2019	Common Stock	15,300	$0.00	0	D
Employee Stock Option (Right to Buy)	$14.92	06/30/2011		J(3)(8)		17,847		02/25/2011(10)	02/25/2019	Common Stock	17,847	$0.00	17,847	D
Employee Stock Option (Right to Buy)	$29.17	06/30/2011		J(3)(8)			16,300	02/24/2011(11)	02/24/2020	Common Stock	16,300	$0.00	0	D
Employee Stock Option (Right to Buy)	$18.28	06/30/2011		J(3)(8)		22,521		02/24/2011(12)	02/24/2020	Common Stock	22,521	$0.00	22,521	D
Employee Stock Option (Right to Buy)	$49.18	06/30/2011		J(8)			13,400	02/23/2012(13)	02/23/2021	Common Stock	13,400	$0.00	0	D
Employee Stock Option (Right to Buy)	$30.81	06/30/2011		J(8)		21,352		02/23/2012(14)	02/23/2021	Common Stock	21,352	$0.00	21,352	D

Explanation of Responses:

1. In connection with the spin-off of Marathon Petroleum Corporation on June 30, 2011 by Marathon Oil Corporation ("MRO"), MRO restricted stock awards of MRO officers or employees, who continued as officers or employees of MRO immediately after the spin-off, were replaced with adjusted MRO restricted stock awards, each of which will generally preserve the value of the original award determined as of the distribution date.

2. Includes dividends of 21.4128 shares previously not reported pursuant to Rule 16a-11.

3. In connection with the spin-off of Marathon Petroleum Corporation ("MPC") on June 30, 2011 by Marathon Oil Corporation ("MRO"), outstanding MRO stock options that are vested, whether held by a current or former officer or employee of MRO or MPC were adjusted, so that the holders hold stock options to purchase both MRO common stock and MPC common stock. The MRO and MPC stock options received, when combined, will generally preserve the instrinsic value of each original stock option grant and the ratio of the exercise price to the fair market value of MRO common stock on the distribution date.

4. Vested in cumulative installments on June 10, 2006, 2007 and 2008, respectively.

5. Vested in cumulative installments on June 1, 2007, 2008 and 2009, respectively.

6. Vested in cumulative installments on May 30, 2008, 2009 and 2010, respectively.

7. Vested in cumulative installments on February 27, 2009, 2010 and 2011, respectively.

8. In connection with the spin-off of Marathon Petroleum Corporation on June 30, 2011 by Marathon Oil Corporation ("MRO"), outstanding MRO stock options that are not vested and are held by MRO officers or employees, who continued as officers or employees of MRO immediately after the spin-off, were replaced with adjusted MRO stock options to purchase MRO common stock, which will generally preserve the intrinsic value of each original stock option grant and the ratio of the exercise price to the fair market value of MRO common stock on the distribution date.

9. Vests in cumulative annual installments of 10,200 and 5,100 shares on February 25, 2011 and 2012, respectively.

10. Vests in cumulative annual installments of 9,709 and 8,138 shares on February 25, 2011 and 2012, respectively.

11. Vests in three cumulative annual installments of 5,433, 5,433 and 5,434 on February 24, 2011, 2012, and 2013, respectively.

12. Vests in three cumulative annual installments of 5,173, 8,673 and 8,675 on February 24, 2011, 2012, and 2013, respectively.

13. Vests in three cumulative annual installments of 4,466, 4,467 and 4,467 on February 23, 2012, 2013, and 2014, respectively.

14. Vests in three cumulative annual installments of 7,116, 7,118 and 7,118 on February 23, 2012, 2013, and 2014, respectively.

Remarks:

	Yvonne R. Kunetka, Attorney-in-Fact for Howard J. Thill	07/05/2011
	** Signature of Reporting Person	Date
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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