Press Release

Ambac Financial Group, Inc. Board of Directors Names Robert J. Genader Chairman

NEW YORK, July 25, 2006 -- Ambac Financial Group, Inc. (NYSE:ABK) today announced that the Board of Directors has unanimously elected Chief Executive Officer and President, Robert J. Genader to the additional post of Chairman, effective immediately. Mr. Genader succeeds Phillip B. Lassiter, who has held the Chairman role at Ambac since the company went public in July 1991. Mr. Lassiter, will remain a member of the Board of Directors of Ambac. Mr. Genader, who has been an officer of the Company since July 1991, has been a member of the Board of Directors since 2001. Mr. Genader was named Chief Executive Officer in January 2004.

Mr. Lassiter commented, "While I have enjoyed the privilege of chairing Ambac's talented Board for the past fifteen years, I am especially pleased to be turning over my chairman duties to my longtime business partner. Bob has amply demonstrated that he is deserving of the title and additional responsibilities."

Mr. Genader commented, "During Phil's many years as Chairman of Ambac, the Company has developed into the clear leader in the financial guaranty industry and a truly global player within the financial services marketplace. Phil's leadership and vision throughout the years have been the guiding force. I am excited to have the opportunity to expand upon this vision and am confident that Ambac will continue to improve upon its excellent record."

The Company also announced that the Board of Directors has named W. Grant Gregory Presiding Director. Mr. Gregory, Chairman of Gregory & Hoenemeyer, Inc., has been a member of Ambac's Board of Directors since 1991.

* * * * * * *

Ambac Financial Group, Inc., headquartered in New York City, is a holding company whose affiliates provide financial guarantees and financial services to clients in both the public and private sectors around the world. Ambac’s principal operating subsidiary, Ambac Assurance Corporation, a leading guarantor of public finance and structured finance obligations, has earned triple-A ratings, the highest ratings available from Moody’s Investors Service, Inc., Standard & Poor’s Ratings Services, Fitch, Inc. and Rating and Investment Information, Inc. Ambac Financial Group, Inc. common stock is listed on the New York Stock Exchange (ticker symbol ABK).