Ownership Submission
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)
06/30/2011
(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

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
Stock Appreciation Right $ 16.805 06/30/2011   J(1)     600,000 05/26/2005(2) 05/26/2014 Common Stock 600,000 $ 0 0 D  
Stock Appreciation Right $ 10.53 06/30/2011   J(1)   571,278   05/26/2007 05/26/2014 Common Stock 571,278 $ 0 571,278 D  
Employee Stock Option (Right to Buy) $ 23.825 06/30/2011   J(3)     353,600 05/25/2006(4) 05/25/2015 Common Stock 353,600 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 14.93 06/30/2011   J(3)   336,696   05/25/2008 05/25/2015 Common Stock 336,696 $ 0 336,696 D  
Employee Stock Option (Right to Buy) $ 37.818 06/30/2011   J(3)     379,600 06/01/2007(5) 06/01/2016 Common Stock 379,600 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 23.69 06/30/2011   J(3)   361,322   06/01/2009 06/01/2016 Common Stock 361,322 $ 0 361,322 D  
Employee Stock Option (Right to Buy) $ 61.05 06/30/2011   J(3)     298,600 05/30/2008(6) 05/30/2017 Common Stock 298,600 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 38.25 06/30/2011   J(3)   284,289   05/30/2010 05/30/2017 Common Stock 284,289 $ 0 284,289 D  
Employee Stock Option (Right to Buy) $ 54.36 06/30/2011   J(3)     223,200 02/27/2009(7) 02/27/2018 Common Stock 223,200 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 34.06 06/30/2011   J(3)   212,341   02/27/2011 02/27/2018 Common Stock 212,341 $ 0 212,341 D  
Employee Stock Option (Right to Buy) $ 23.82 06/30/2011   J(3)(8)     470,200 02/25/2010(9) 02/25/2019 Common Stock 470,200 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 14.92 06/30/2011   J(3)(8)   548,486   02/25/2011(10) 02/25/2019 Common Stock 548,486 $ 0 548,486 D  
Employee Stock Option (Right to Buy) $ 29.17 06/30/2011   J(3)(8)     545,100 02/24/2011(11) 02/24/2020 Common Stock 545,100 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 18.28 06/30/2011   J(3)(8)   753,204   02/24/2011(12) 02/24/2020 Common Stock 753,204 $ 0 753,204 D  
Employee Stock Option (Right to Buy) $ 49.18 06/30/2011   J(3)(8)     402,900 02/23/2012(13) 02/23/2021 Common Stock 402,900 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 30.81 06/30/2011   J(3)(8)   642,054   02/23/2012(14) 02/23/2021 Common Stock 642,054 $ 0 642,054 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

 Yvonne R. Kunetka, Attorney-in-Fact for Clarence P. Cazalot, Jr.   07/05/2011
**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) In connection with the spin-off of Marathon Petroleum Corporation ("MPC") on June 30, 2011 by Marathon Oil Corporation ("MRO"), outstanding vested MRO stock appreciation rights (SARs) were replaced with both adjusted MRO SARs and MPC SARs. Both SARs, when combined, will generally preserve the aggregate instrinsic value of each original SAR grant. They will also generally preserve the ratio of exercise price to the fair market value of MRO common stock on the distribution date.
(2) Vested in cumulative installments on May 26, 2005, 2006 and 2007, respectively.
(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 May 25, 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 156,733, 156,733 and 156,734 shares on February 25, 2010, 2011 and 2012, respectively.
(10) Vests in cumulative annual installments of 298,383 and 250,103 shares on February 25, 2011 and 2012, respectively.
(11) Vests in three cumulative annual installments of 181,700, 181,700 and 181,700 shares on February 24, 2011, 2012, and 2013, respectively.
(12) Vests in three cumulative annual installments of 173,026, 290,089 and 290,089 shares on February 24, 2011, 2012, and 2013, respectively.
(13) Vests in cumulative annual installments of 134,300, 134,300 and 134,300 shares on February 23, 2012, 2013 and 2014, respectively.
(14) Vests in cumulative annual installments of 214,018, 214,018 and 214,018 shares on February 23, 2012, 2013 and 2014, respectively.

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