X0306 4 2013-05-01 1 0001141719 ALTERRA CAPITAL HOLDINGS Ltd ALTE 0001198112 FORRESTER W THOMAS C/O ALTERRA CAPITAL HOLDINGS LIMITED ALTERRA HOUSE, 2 FRONT STREET HAMILTON, BERMUDA D0 HM 11 BERMUDA 1 0 0 0 Common Shares 2013-05-01 4 D 0 14000 D 0 D Disposed of pursuant to the Agreement and Plan of Merger, dated as of December 18, 2012 (the "Merger Agreement") between Alterra Capital Holdings Limited (the "Issuer"), Markel Corporation ("Markel") and Commonwealth Merger Subsidiary Limited in exchange on a per share basis for (i) the amount of shares of Markel common stock equal to the number of shares of Issuer common stock multiplied by 0.04315 plus (ii) $10.00 in cash, without interest, together with any cash paid in lieu of fractional shares relating to each award and form of ownership. All of the shares of common stock of the Issuer exchanged represented restricted stock that automatically vested upon the closing of the transactions contemplated by the Merger Agreement. H. Matthew Crusey, Attorney-in-Fact 2013-05-03