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 *
BEHRMAN PHILIP G
  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)
Sr. Vice Pres., WW Exploration
(Last)
(First)
(Middle)
C/O MARATHON OIL CORPORATION, 5555 SAN FELIPE ROAD
3. Date of Earliest Transaction (Month/Day/Year)
05/11/2005
(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
COMMON STOCK 05/11/2005   M   30,000 A $ 26.4375 68,001.821 D  
COMMON STOCK 05/11/2005   S   4,000 D $ 48.51 64,001.821 D  
COMMON STOCK 05/11/2005   S   15,000 D $ 48.52 49,001.821 D  
COMMON STOCK 05/11/2005   S   9,000 D $ 48.53 40,001.821 D  
COMMON STOCK 05/11/2005   S   2,000 D $ 48.54 38,001.821 D  
COMMON STOCK               200 I By Family Living Trust (1)

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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) $ 26.4375 05/11/2005   M(2)     30,000 09/25/2001(3) 09/25/2010 COMMON STOCK 30,000 $ 0 0 D  
STOCK APPRECIATION RIGHT $ 26.4375 05/11/2005   M(2)     30,000 09/25/2001(3) 09/25/2010 COMMON STOCK 30,000 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BEHRMAN PHILIP G
C/O MARATHON OIL CORPORATION
5555 SAN FELIPE ROAD
HOUSTON, TX 77056
      Sr. Vice Pres., WW Exploration  

Signatures

 Richard J. Kolencik, Attorney-in-Fact for Philip G. Behrman   05/12/2005
**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) These shares are held in The Jacqueline L. Delany Trust, pursuant to a Trust Agreement dated May 30, 2003 between Jacqueline L. Delany, as Trustor and Joan Marie Delany, as trustee. The reporting person's mother-in-law is the beneficiary of the trust. The reporting person's spouse is the trustee of the trust and holds a remainder interest therein. The reporting person disclaims beneficial ownership of the reported securities except to the extent of his and/or his spouse's pecuniary interest therein.
(2) Exercise of stock option and cancellation of tandem stock appreciation right.
(3) Vests in three equal annual installments on September 25, 2001, 2002, and 2003.

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