Alterra Capital Holdings Limited (“Alterra”) (NASDAQ: ALTE; BSX: ALTE.BH) today announced that Stephen J. Vaccaro Jr., Chairman of US Insurance, will retire effective July 1, 2012. Alterra US Insurance is led by Doug Worman, Executive Vice President of Alterra and Chief Executive Officer of Alterra US Insurance, and Bryan Sanders, Chief Executive Officer of Alterra Specialty, Alterra’s US specialty insurance operation that focuses principally on the wholesale distribution segment. Steve Vaccaro joined Alterra in 2006 and was instrumental in the development of Alterra’s US insurance operations. Prior to his appointment as Chairman of US Insurance in 2011, Steve served as Chief Executive Officer of Alterra Specialty. W. Marston (Marty) Becker, President and Chief Executive Officer of Alterra, said “On behalf of all of us at Alterra, I want to thank Steve for his dedicated service to our company and for his leadership in positioning and building our US insurance franchise. Steve’s career in the commercial insurance marketplace has spanned some 40 years, and he has made an important contribution to the excess and surplus lines segment. His legacy at Alterra includes a talented group of underwriters and professionals who are well positioned to successfully grow Alterra’s US Insurance business.” Alterra US Insurance, which includes Alterra Specialty, has approximately 150 employees operating from eight offices located throughout the US. In 2011, gross premiums written by Alterra US Insurance amounted to $375 million. About Alterra Capital Holdings Limited 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.