Platinum Underwriters Holdings Sees Loss of $87M from Japan Earthquake and Tsunami

Platinum Underwriters Holdings, Ltd.

announced today that it expects the Tohoku earthquake and related tsunami that struck the northeastern coast of Japan on March 11, 2011 will have a net negative impact of approximately $87 million on the Company's first quarter 2011 results. The net negative impact of this event includes an estimate of losses and loss adjustment expenses, net of retrocessional coverage, reinstatement premiums, taxes and the expected impact of foreign exchange rates. The Company's preliminary estimate is based on the Company's portfolio modeling, currently available industry loss estimates, market share analysis and a review of the Company's in-force contracts, as well as initial discussions with brokers and clients. The Company's assessment of its exposure to this event is ongoing. The actual net negative impact of the event on the Company's results may differ materially from the Company's estimate due to the inherent uncertainties of making such estimates, including the preliminary nature of available information, the use of portfolio models in the estimation process and potential inaccuracies and inadequacies in data provided by clients and brokers.