Alterra Capital 8-K Alterra Capital Reports First Quarter 2011 Results

Exhibit 99.3

ALTERRA CAPITAL ANNOUNCES $0.12 DIVIDEND

HAMILTON, BERMUDA, May 3, 2011—Alterra Capital Holdings Limited (NASDAQ: ALTE; BSX: ALTE.BH) (“Alterra”) announced today that Alterra’s Board of Directors declared a dividend of $0.12 per share. The dividend is payable on May 31, 2011, to shareholders of record as of May 17, 2011.

Alterra Capital Holdings Limited is a global enterprise dedicated to providing diversified specialty insurance and reinsurance products to corporations, public entities and property and casualty insurers. Alterra was formed on May 12, 2010 by the merger of Max Capital Group Ltd. and Harbor Point Limited.

Contacts Susan Spivak Bernstein Senior Vice President susan.spivak@alterra-bm.com 1-212-898-6640 Roanne Kulakoff or Peter Hill Kekst and Company roanne-kulakoff@kekst.com peter-hill@kekst.com 1-212-521-4800