SecProbe.io

April 21, 2011
 Via E-mail

Brian F. Maxted Chief Executive Officer Kosmos Energy Ltd. 8176 Park Lane, Suite 500 Dallas, Texas 75231
Re: Kosmos Energy Ltd.
Amendment No. 4 to Registrati on Statement on Form S-1
Filed April 14, 2011
  File No. 333-171700

Dear Mr. Maxted:

We have reviewed your letter dated Ap ril 19, 2011, and we have the following
comments.  In some of our comments, we may ask you to provide us with information so we may better understand your disclosure.
 Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe  our comments apply to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.

After reviewing any amendment to your re gistration statement and the information you
provide in response to these comments, we may have additional comments.
 Amendment No. 4 to Registration Statement on Form S-1

 Results of Operations, page 60

 Year Ended December 31, 2010 vs. 2009, page 60

 Doubtful Accounts Expense, page 61

1. We note your response to prior comments one through five.  Please e xpand your critical
accounting policies discussion within management’s discussion and analysis, and

Brian F. Maxted
Kosmos Energy Ltd. April 21, 2011 Page 2
 elsewhere as applicable, to  provide the following:

• explain why provisions for default we re not contemplated in the 2004 EO
Agreement,
• explain how the potential sale  of the EO Group’s interest  in the WCTP Petroleum
Agreement will impact the recovery of the reimbursable portion of the EO
Group’s carried interest,
• explain if you intend to bri ng a breach of contract dis pute in an international
arbitration proceeding against the EO  Group, if you do not, explain why not,
• given the commencement of production at J ubilee, and the sale of the EO Group’s
oil production, explain in more detail w hy you do not expect to fully recover the
reimbursable portion of the EO  Group’s carried interest,
• explain the specific facts and circumstan ces that led you to conclude that an
allowance of $39.8 million is the best es timate of the potential uncollectible
amounts at December 31, 2010, and
• explain what specific factors will allo w you to recover the remaining unreserved
balance.
As part of your response, please file as an e xhibit the EO Agreement that establishes your
obligation to carry EO Group’s 3.5% interest.
Notes to Consolidated Financial Statements, page F-8

 Note 16 Income Taxes, page F-31

 2. We note your response to prior comments 10 and 11.  Please expand your disclosure to
discuss the significant assumptions and estimates  made that led you to conclude that at
December 31, 2010 it was more likely than no t the deferred tax asset for your Ghana
operations would be realized.  Such disclosu re should include, but not be limited to, the
information provided in your response, and th at discussed via tel econference with the
Staff on April 20, 2011.
 Closing Comments

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing incl udes the information the Securities Act of 1933 and
all applicable Securities Act rules require.  Since the company and its management are in
possession of all facts relating to a company’s disc losure, they are responsible for the accuracy
and adequacy of the disclosures they have made.     Please refer to Rules 460 and 461 regarding re quests for acceleration.  We will consider a
written request for acceleration of  the effective date of the regi stration statement as confirmation
of the fact that those reques ting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Excha nge Act of 1934 as they relate to the proposed

Brian F. Maxted
Kosmos Energy Ltd. April 21, 2011 Page 3
 public offering of the securities specified in th e above registration stat ement.  Please allow
adequate time for us to review any amendment prior to the requested effective date of the
registration statement.
You may contact James Murphy, Petroleum E ngineer, at (202) 551- 3703 with questions
about engineering comments.  You may contact Ma rk Wojciechowski, Staff Accountant, at (202)
551-3759 or Mark Shannon, Branch Chief, at (2 02) 551-3299 if you have questions regarding
comments on the financial statements and rela ted matters.  Please contact Alexandra M.
Ledbetter, Staff Attorney, at (202) 551-3317 or me at (202) 551-3740 with any other questions.

Sincerely,
  /s/ Mark C. Shannon  -for-
H. Roger Schwall Assistant Director