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 *
THORN WRAY T
  2. Issuer Name and Ticker or Trading Symbol
Flagstone Reinsurance Holdings Ltd [FSR]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O FLAGSTONE REINSURANCE HOLDINGS LTD, 23 CHURCH STREET
3. Date of Earliest Transaction (Month/Day/Year)
09/10/2009
(Street)

HAMILTON, D0 D0 HM11
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 Shares 09/10/2009   J(1)   91,301 D $ 10.5432 4,024,519 I See Footnotes (2)

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

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
THORN WRAY T
C/O FLAGSTONE REINSURANCE HOLDINGS LTD
23 CHURCH STREET
HAMILTON, D0 D0 HM11
  X      

Signatures

 /s/ Wray T. Thorn   09/11/2009
**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) Represents a sale by Marathon Special Opportunity Master Fund, Ltd. (the "Master Fund") and/or Marathon Special Opportunity Liquidating Fund, Ltd. (the "Liquidating Fund" and together with the Master Fund, the "Funds").
(2) As of September 10, 2009, the Funds held, in the aggregate, 4,024,519 common shares of Flagstone Reinsurance Holdings Limited (the "Company"). The reporting person is a director of the Company. The reporting person does not individually hold or otherwise beneficially own any securities of the Company. The reporting person is an employee of Marathon Asset Management, LP (formerly known as Marathon Asset Management, LLC, the "Investment Manager"), which serves as the investment manager of the Funds. The Funds own certain securities of the Company, all of which are subject to the sole voting and investment authority of the Investment Manager. Thus, for the purposes of Reg. Section 240.13d-3, the Investment Manager is deemed to beneficially own the securities of the Company held by the Funds, and the reporting person disclaims beneficial ownership of the securities of the Company held by the Funds.

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