X0304 4 2012-02-23 0 0001171500 PLATINUM UNDERWRITERS HOLDINGS LTD PTP 0001241514 SCHMIDT NEAL J PLATINUM ADMINISTRATIVE SERVICES, INC. 2 WORLD FINANCIAL CENTER, SUITE 2300 NEW YORK NY 10281 0 1 0 0 EVP and Chief Actuary - PASI Common Shares 2012-02-23 4 M 0 2552 0.00 A 53574 D Common Shares 2012-02-23 4 F 0 921 35.50 D 52653 D Common Shares 2012-02-23 4 A 0 2117 0.00 A 54770 D Common Shares 2012-02-23 4 F 0 764 35.50 D 54006 D Share units 2012-02-23 4 M 0 2552 0.00 D Common Shares 2552 2552 D These common shares represent the payment of an award granted on February 23, 2009 under the Amended and Restated Executive Incentive Plan of Platinum Underwriters Holdings, Ltd. (the "Company") for the 2009-2011 performance cycle. 1-for-1 These share units were awarded on February 23, 2009 under the Company's 2006 Share Incentive Plan (the "Plan"). On February 23, 2012, the third quarter of these share units vested and the Company issued to the reporting person one Common Share for each vested share unit, reduced by the number of Common Shares which are equal in Fair Market Value (as defined in the Plan) on such date to the reporting person's tax withholding obligation. The remaining quarter of the share units will vest on the fourth anniversary of the date of award and on that vesting date the Company will issue to the reporting person one Common Share for each vested share unit. /s/ Christina M. Parker, Attorney-in-Fact 2012-02-24