Date: December 19, 2012Time: 11:00 a.m. Eastern TimeToll-free number (U.S. callers): 1-877-407-9205International callers: 1- 201-689-8054Please dial in five to ten minutes prior to the start of the call. In addition, interested persons may listen to the call via the websites of Markel and Alterra at www.markelcorp.com and www.alterracap.com, respectively. About Markel Corporation: Markel Corporation is a diverse financial holding company serving a variety of niche markets. The Company's principal business markets and underwrites specialty insurance products. In each of the Company's businesses, it seeks to provide quality products and excellent customer service so that it can be a market leader. The financial goals of the Company are to earn consistent underwriting and operating profits and superior investment returns to build shareholder value. Visit Markel Corporation on the web at www.markelcorp.com. 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. Visit Alterra on the web at www.alterracap.com. INFORMATION CONCERNING FORWARD-LOOKING STATEMENTS This release includes statements about future economic performance, finances, expectations, plans and prospects of Alterra and Markel, both individually and on a combined basis, that are forward-looking statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. There are risks and uncertainties that could cause actual results to differ materially from those expressed in or suggested by such statements. For further information regarding factors affecting future results of Alterra and Markel, please refer to their Annual Report on Form 10-K for the year ended December 31, 2011 and Quarterly Reports on Form 10-Q and other documents filed by Alterra and Markel since March 1, 2012 with the Securities Exchange Commission (“SEC”). These documents are also available free of charge, in the case of Alterra, by directing a request to Alterra through Joe Roberts, Chief Financial Officer, or Susan Spivak Bernstein, Senior Vice President, Investor Relations, at 441-295-8800 and, in the case of Markel, by directing a request to Bruce Kay, Investor Relations, at 804-747-0136. Neither Alterra nor Markel undertakes any obligation to update or revise publicly any forward-looking statement whether as a result of new information, future developments or otherwise.