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, S.A. [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 SA, 37, VAL ST. ANDRE
3. Date of Earliest Transaction (Month/Day/Year)
05/12/2011
(Street)

L-1128 LUXEMBOURG, N4 
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

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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
Restricted Share Units $ 0 (1) 05/12/2011   A   6,825   05/12/2011(2)   (3) Common Shares 6,825 $ 0 (1) 6,825 D  
Restricted Share Units $ 0 (1)               (2)   (3) Common Shares 34,426   34,426 I By Marathon Special Opportunity Master Fund, Ltd. (4)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
THORN WRAY T
C/O FLAGSTONE REINSURANCE HOLDINGS SA
37, VAL ST. ANDRE
L-1128 LUXEMBOURG, N4 
  X      

Signatures

 /s/ Thorn Wray   05/16/2011
**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) Each Restricted Share Unit ("RSU") represents the right to receive, without payment to the Company, one newly issued, fully paid and non-assessable common share of the Company, subject to the terms and conditions of the RSU Plan and grant certificate evidencing each grant. In the discretion of the Compensation Committee, upon exercise, the RSU grant may alternatively be paid in cash or partly in cash and partly in common shares.
(2) The RSUs vest 100% on the date of the grant.
(3) The RSUs have no expiry date.
(4) The reporting person is an employee of Marathon Asset Management, LP (the "Investment Manager"), which serves as the investment manager of Marathon Special Opportunity Master Fund, Ltd. and Marathon Special Opportunity Liquidating Fund, Ltd. (together, the "Funds"). Securities of the Company that are held by the Funds are subject to the sole voting and investment authority of the Investment Manager, and the reporting person disclaims beneficial ownership of any securities of the Company held by the Funds except to the extent of his pecuniary interest, if any, therein.

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