Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported):   January 22, 2013

Alterra Capital Holdings Limited
(Exact name of registrant as specified in its charter)

Bermuda 000-33047 98-0584464
(State or other jurisdiction
(I.R.S. Employer
of incorporation) File Number) Identification No.)
Alterra House, 2 Front Street, Hamilton, Bermuda   HM 11
(Address of principal executive offices)
(Zip Code)
Registrant’s telephone number, including area code:   (441) 295-8800

Not Applicable
Former name or former address, if changed since last report


Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[x]  Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
[  ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
[  ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
[  ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01 Other Events.

On January 22, 2013, Alterra Capital Holdings Limited ("Alterra") received confirmation of the early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the "HSR Act"), with respect to the transactions contemplated by the Agreement and Plan of Merger, dated as of December 18, 2012, among Alterra, Markel Corporation ("Markel") and Commonwealth Merger Subsidiary Limited, a wholly owned subsidiary of Markel (the "Merger Agreement"). Expiration or termination of the HSR Act waiting period is one of the closing conditions under the Merger Agreement. Alterra previously announced its entry into the Merger Agreement.


This filing 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 respective 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.

This filing contains certain forward-looking statements within the meaning of the U.S. federal securities laws. Statements that are not historical facts, including statements about Alterra’s and Markel’s beliefs, plans or expectations, are forward-looking statements. These statements are based on Alterra’s or Markel’s current plans, estimates and expectations. Some forward-looking statements may be identified by use of terms such as “believe,” “anticipate,” “intend,” “expect,” “project,” “plan,” “may,” “should,” “could,” “will,” “estimate,” “predict,” “potential,” “continue,” and similar words, terms or statements of a future or forward-looking nature. In light of the inherent risks and uncertainties in all forward-looking statements, the inclusion of such statements in this filing should not be considered as a representation by Alterra, Markel or any other person that Alterra’s or Markel’s objectives or plans, both individually and on a combined basis, will be achieved. A non-exclusive list of important factors that could cause actual results to differ materially from those in such forward-looking statements includes the following: (a) the occurrence of natural or man-made catastrophic events with a frequency or severity exceeding expectations; (b) the adequacy of loss reserves and the need to adjust such reserves as claims develop over time; (c) the failure of any of the loss limitation methods the parties employ; (d) any adverse change in financial ratings of either company or their subsidiaries; (e) the effect of competition on market trends and pricing; (f) cyclical trends, including with respect to demand and pricing in the insurance and reinsurance markets; (g) changes in general economic conditions, including changes in interest rates and/or equity values in the United States of America and elsewhere; and (h) other factors set forth in Alterra’s and Markel’s recent reports on Form 10-K, Form 10-Q and other documents filed with the SEC by Alterra and Markel.

* * * * *

Risks and uncertainties relating to the proposed transaction include the risks that: (1) the parties will not obtain the requisite shareholder or regulatory approvals for the transaction; (2) the anticipated benefits of the transaction will not be realized or the parties may experience difficulties in successfully integrating the two companies; (3) the parties may not be able to retain key personnel; (4) the conditions to the closing of the proposed merger may not be satisfied or waived; (5) the outcome of any legal proceedings to the extent initiated against Alterra or Markel or its respective directors and officers following the announcement of the proposed merger is uncertain; (6) the acquisition may involve unexpected costs; and (7) the businesses may suffer as a result of uncertainty surrounding the acquisition. These risks, as well as other risks of the combined company and its subsidiaries may be different from what the companies expect, or have previously experienced, and each party’s management may respond differently to any of the aforementioned factors. These risks, as well as other risks associated with the merger, are more fully discussed in the joint proxy statement/prospectus of Markel and Alterra that has been filed with the SEC. Readers are cautioned not to place undue reliance on any forward-looking statements, which speak only as of the date on which they are made.


This filing relates to a proposed merger between Alterra and Markel. On December 27, 2012, Markel filed with the SEC a registration statement on Form S-4, and on January 18, 2013, Markel and Alterra each filed the definitive joint proxy statement/prospectus. This filing is not a substitute for the definitive joint proxy statement/prospectus or any other document that Markel or Alterra filed or may file with the SEC or send to its shareholders in connection with the proposed merger. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE DEFINITVE JOINT PROXY STATEMENT/PROSPECTUS AND ALL OTHER RELEVANT DOCUMENTS FILED OR THAT MAY BE FILED WITH THE SEC OR SENT TO SHAREHOLDERS AS THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED MERGER. All documents, when filed, will be available free of charge at the SEC’s website (www.sec.gov) or, in the case of Alterra, by directing a request to 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.


Alterra and Markel and their respective directors and executive officers may be deemed to be participants in any solicitation of proxies from both Alterra’s and Markel’s shareholders in favor of the proposed transaction. Information about Alterra’s directors and executive officers and their ownership in Alterra common stock is available in the proxy statement dated March 26, 2012 for Alterra’s 2012 annual general meeting of shareholders. Information about Markel’s directors and executive officers and their ownership of Markel common stock is available in the proxy statement dated March 16, 2012 for Markel’s 2012 annual meeting of shareholders.


Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

    Alterra Capital Holdings Limited
January 23, 2013   By:   /s/ Peter A. Minton
        Name: Peter A. Minton
        Title: Executive Vice President and Chief Operating Officer