LETTER OF TRANSMITTAL

for

Tender of All Outstanding

Series A 7.50% Notes due June 1, 2017

in Exchange for

Series B 7.50% Notes due June 1, 2017

of

Platinum Underwriters Finance, Inc.

Unconditionally Guaranteed by

Platinum Underwriters Holdings, Ltd.

The Exchange Agent (the Exchange Agent) is:

JPMORGAN CHASE BANK, N.A.

For Delivery by Regular, Registered or Certified Mail, or Overnight Delivery:

JPMorgan Chase Bank, N.A.

2001 Bryant Street  10th Floor

Dallas, Texas 75201

Attention: Worldwide Securities Services

By Hand:

JPMorgan Chase Bank, N.A.

4 New York Plaza

Ground Floor Window

New York, New York 10004

Attention: Worldwide Securities Services

By Facsimile Transmission (for Eligible Guarantor Institutions Only):

(214) 468-6494

Attention: Frank Ivins

For Information Call:

(800) 275-2048

Attention: Customer Service

For Confirmation by Telephone:

(214) 468-6464

Attention: Frank Ivins

DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE OR TRANSMISSION VIA FACSIMILE TRANSMISSION TO A NUMBER OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY.

      The undersigned acknowledges receipt of the Prospectus dated [ ], 2005 (the Prospectus) of Platinum Underwriters Finance, Inc. (Platinum Finance) and Platinum Underwriters Holdings, Ltd. (Platinum Holdings), and this Letter of Transmittal (the Letter of Transmittal), which together describe the offer to exchange (the Exchange Offer) the outstanding Series A 7.50% Notes due June 1, 2017 issued by Platinum Finance and unconditionally guaranteed by Platinum Holdings (the Outstanding Notes) for the Series B 7.50% Notes due June 1, 2017 issued by Platinum Finance and unconditionally guaranteed by Platinum Holdings (the Exchange Notes and, together with the Outstanding Notes, the Notes), which have been registered under the Securities Act of 1933, as amended (the Securities Act), from the holders thereof. Platinum Finance is a wholly-owned indirect subsidiary of Platinum Holdings.

      The terms of the Exchange Notes are identical in all material respects (including principal amount, interest rate and maturity) to the terms of the Outstanding Notes for which they may be exchanged pursuant to the Exchange Offer, except that the Exchange Notes are freely transferable by holders thereof (except as provided herein or in the Prospectus) and are not subject to certain covenants regarding registration under the Securities Act.

      Capitalized terms used but not defined herein shall have the same meaning given them in the Prospectus.

      YOUR BANK OR BROKER CAN ASSIST YOU IN COMPLETING THIS FORM. THE INSTRUCTIONS INCLUDED WITH THIS LETTER OF TRANSMITTAL MUST BE FOLLOWED. QUESTIONS AND REQUESTS FOR ASSISTANCE OR FOR ADDITIONAL COPIES OF THE PROSPECTUS AND THIS LETTER OF TRANSMITTAL MAY BE DIRECTED TO THE EXCHANGE AGENT.

      The undersigned has checked the appropriate boxes below and signed this Letter of Transmittal to indicate the action the undersigned desires to take with respect to the Exchange Offer.

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