Transatlantic Board of Directors to Review Unsolicited Exchange Offer from Validus

Transatlantic Holdings, Inc.

today confirmed that Validus Holdings, Ltd.

has commenced an unsolicited exchange offer to acquire all outstanding common shares of Transatlantic. Pursuant to the Validus exchange offer, Transatlantic stockholders would receive 1.5564 Validus voting common shares and $8.00 in cash for each share of Transatlantic common stock held. As previously announced, Transatlantic entered into a definitive merger agreement with Allied World Assurance Company Holdings, AG

on June 12, 2011, under which Transatlantic and Allied World would combine in a merger of equals, with stockholders of Transatlantic receiving 0.88 Allied World common shares for each share of Transatlantic common stock. The Transatlantic Board of Directors reaffirms its recommendation of, and its declaration of advisability with respect to, the Allied World Merger Agreement.