October 23, 2006

H. Roger Schwall, Assistant Director
Shannon Buskirk
April Sifford, Branch Chief
United States Securities and Exchange Commission
Division of Corporation Finance
100 F Street, N.E., mail stop 7010
Washington, DC 20549

Re: Marathon Oil Corporation
Form 10-K for the fiscal year ended December 31, 2005
Filed March 6, 2006
Supplemental Responses filed on June 2, 2006, July 14, 2006 and August 31, 2006
File No. 001-05153

Dear Mr. Schwall, Ms. Buskirk and Ms. Sifford:

     This is to confirm my conversation with Ms. Shannon Buskirk of Marathon’s proposed date to file its response to the SEC’s comment letter dated October 16, 2006. As discussed, Marathon intends to file its response on Friday, November 10, 2006. This date was acceptable to Ms. Buskirk.

     Please call the undersigned at 713-296-2535, if you have any questions regarding this submission.

Very truly yours,
 

/s/ Richard T. Kolencik

Richard J. Kolencik 

General Attorney