Press Release

Ambac Financial Group, Inc. Conference Call to Discuss Second Quarter Earnings Set for July 25 At 11 A.M. EST

NEW YORK, July 11, 2007 -- Ambac Financial Group, Inc. (NYSE:ABK) announced that it will host a conference call for investors on July 25 at 11 a.m. EST to discuss second quarter 2007 earnings which are scheduled to be released at 6 a.m. that morning. The dial in number for the call is 877-407-8035 (domestic) and 201-689-8035 (international).

The conference call will also be broadcast live on Ambac’s website at ‘www.ambac.com’.

Beginning at 2 p.m. on July 25, and running through August 3, the conference call will be available in replay. The replay numbers are 877-660-6853 (domestic) and 201-612-7415 (international). The account and confirmation numbers for the replay are 286 and 225610, respectively. A recording will also be available on Ambac’s web site approximately one hour after the end of the conference call.

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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, and Fitch, Inc. Ambac Financial Group, Inc. common stock is listed on the New York Stock Exchange (ticker symbol ABK).