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                                                                    Exhibit 31.2


                    CERTIFICATION OF CHIEF FINANCIAL OFFICER


I, Joseph F. Fisher, certify that:

1.    I have reviewed this Annual Report on Form 10-K for the fiscal year ended
      December 31, 2005 (this "Report") of Platinum Underwriters Holdings, Ltd.
      (the "Registrant");

2.    Based on my knowledge, this Report does not contain any untrue statement
      of a material fact or omit to state a material fact necessary to make the
      statements made, in light of the circumstances under which such statements
      were made, not misleading with respect to the period covered by this
      Report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this Report, fairly present in all material
      respects the financial condition, results of operations and cash flows of
      the Registrant as of, and for, the periods presented in this Report;

4.    The Registrant's other certifying officer and I are responsible for
      establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
      control over financial reporting (as defined in Exchange Act Rules
      13a-15(f) and 15d-15(f)) for the Registrant and have:

      a)   Designed such disclosure controls and procedures, or caused such
           disclosure controls and procedures to be designed under our
           supervision, to ensure that material information relating to the
           Registrant, including its consolidated subsidiaries, is made known to
           us by others within those entities, particularly during the period in
           which this Report is being prepared;

      b)   Designed such internal control over financial reporting, or caused
           such internal control over financial reporting to be designed under
           our supervision, to provide reasonable assurance regarding the
           reliability of financial reporting and the preparation of financial
           statements for external purposes in accordance with generally
           accepted accounting principles;

      c)   Evaluated the effectiveness of the Registrant's disclosure controls
           and procedures and presented in this Report our conclusions about the
           effectiveness of the disclosure controls and procedures, as of the
           end of the period covered by this Report based on such evaluation;

      d)   Disclosed in this Report any change in the Registrant's internal
           control over financial reporting that occurred during the
           Registrant's most recent fiscal quarter (the Registrant's fourth
           fiscal quarter in the case of an annual Report) that has materially
           affected, or is reasonably likely to materially affect, the
           Registrant's internal control over financial reporting; and

5.    The Registrant's other certifying officer and I have disclosed, based on
      our most recent evaluation of internal control over financial reporting,
      to the Registrant's auditors and the audit committee of the Registrant's
      board of directors (or persons performing the equivalent functions):

      a)   All significant deficiencies and material weaknesses in the design or
           operation of internal control over financial reporting which are
           reasonably likely to adversely affect the Registrant's ability to
           record, process, summarize and report financial information; and

      b)   Any fraud, whether or not material, that involves management or other
           employees who have a significant role in the Registrant's internal
           control over financial reporting.


February 26, 2006           /s/  JOSEPH F. FISHER
                            ----------------------------------------------------
                            By: Joseph F. Fisher
                            Executive Vice President and Chief Financial Officer