Ambac Implements New SEC Rule for Internet Posting of Proxy Materials

NEW YORK.- Ambac Financial Group, Inc. (NYSE:ABK) (Ambac) today began mailing the “Notice of Internet Availability of Proxy Materials” for its 2008 Annual Meeting of Stockholders under the new Notice and Access rule of the U.S. Securities and Exchange Commission (“SEC”).

Ambac is one of the earliest of the large accelerated filers to implement the SEC’s new rule which allows companies to furnish proxy materials to stockholders via the Internet as an alternative to the traditional approach of mailing printed copies. The proxy statement for the 2008 annual meeting and the 2007 Annual Report on Form 10-K as filed with the SEC for the fiscal year ended December 31, 2007 are available under “2008 Proxy Materials” in the Investor Relations section of Ambac’s website, www.ambac.com. Ambac stockholders may also obtain printed copies of the Company’s proxy materials for the 2008 annual meeting free of charge by following the instructions provided in the “Notice of Internet Availability of Proxy Materials” that was mailed to stockholders on or about April 21, 2008.

The Company’s Annual Meeting of Stockholders will be held on Tuesday, June 3, 2008 at 11:30 am EST at One State Street Plaza, New York, New York.