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 *
Boisvert Patrick
  2. Issuer Name and Ticker or Trading Symbol
Flagstone Reinsurance Holdings Ltd [FSR]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Financial Officer
(Last)
(First)
(Middle)
FLAGSTONE REINSURANCE HOLDINGS LTD, CRAWFORD HOUSE, 23 CHURCH STREET
3. Date of Earliest Transaction (Month/Day/Year)
12/08/2008
(Street)

HAMILTON, 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

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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
Performance Share Units $ 0 (1) 12/08/2008   J(2)     87,174   (3)   (4) Common Shares 87,174 (5) $ 0 (1) 0 I By Trust (6)
Performance Share Units $ 0 (1) 12/08/2008   A   44,867   01/01/2011(7) 04/01/2011(8) Common Shares 44,867 (5) $ 0 (1) 44,867 I By Trust (6)
Performance Share Units $ 0 (1) 12/08/2008   A   44,867   01/01/2012(7) 04/01/2012(8) Common Shares 44,867 (5) $ 0 (1) 89,734 I By Trust (6)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Boisvert Patrick
FLAGSTONE REINSURANCE HOLDINGS LTD
CRAWFORD HOUSE, 23 CHURCH STREET
HAMILTON, D0 HM11
      Chief Financial Officer  

Signatures

 /s/ Jean-Paul Dyer by power of attorney   12/10/2008
**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) Vesting of Performance Share Units ("PSUs") is contingent upon the reporting person's continued employment with Flagstone Reinsurance Holdings Limited (the "Company") and the Company meeting certain fully diluted return-on-equity ("FDROE") goals. Upon vesting, the PSU holder is entitled to receive a number of common shares of the Company (or the cash equivalent, at the election of the Company) equal to the product of the number of PSUs granted multiplied by a factor based on the Company's FDROE during the vesting period. The factor with respect to the PSUs to be cancelled (see note (2) below) ranged between zero and two, depending on the FDROE achieved during the vesting period. The factor with respect to the current PSUs granted (see note (5) below) will range between 0.5 and 1.5, depending on the FDROE achieved during the vesting period.
(2) The Compensation Committee of the Board of Directors of the Company reviews its assumptions in relation to the PSUs on a quarterly basis. At a meeting of the Compensation Committee of the Board of Directors on November 13, 2008, the members of the Compensation Committee voted to cancel the PSUs previously granted to Mr. Boisvert in light of the Company's current FDROE estimates, subject to receiving Mr. Boisvert's consent. On December 8, 2008, Mr. Boisvert provided his consent and the PSUs previously granted were cancelled.
(3) The total PSUs held by Mr. Boisvert were granted under different series, with different vesting contingencies described in note 1 above. Subject to the contingencies described in note 1 above and the other terms and conditions of the issuer's PSU Plan, 25,000 of these shares would have vested on December 31, 2008; 42,174 of these shares would have vested on December 31, 2009 and 20,000 of these shares would have vested on December 31, 2010.
(4) Assuming the Company would settle these PSUs within three months of the vesting date, 25,000 of these shares would have expired on March 31, 2009; 42,174 of these shares would have expired on March 31, 2010 and 20,000 of these shares would have expired on March 31, 2011.
(5) Represents the mid-point of the vesting range described in note 1 above for these PSUs.
(6) These PSU grants are held through a trust for the benefit of others and Mr. Boisvert therefore disclaims beneficial ownership of these PSUs.
(7) These PSUs would have vested, subject to the contingency described in note 1 above and the other terms and conditions of the Company's PSU Plan, on the date shown.
(8) Assumes the Company would settle these PSUs within three months of the vesting date.

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