Ambac Financial Group, Inc. (NYSE: ABK) (Ambac) today announced the appointment of David W. Wallis as Chief Risk Officer. In this newly created role, David will be responsible for three principal areas: Capital and Risk Analysis, Portfolio Risk Management and Credit Risk Management. While David previously had responsibility for Portfolio Risk Management, the addition of Credit Risk Management and a greater focus on capital will greatly enhance Ambac’s ability to strengthen its underwriting process while retaining its focus on risk-return driven capital management.

Bob D. Selvaggio will head Capital and Risk Analysis, while Cathy J. Matanle will head Portfolio Risk Management, both reporting to Mr. Wallis. The Credit Risk Management group will retain distinct Public and Structured Finance reporting lines such that each will maintain their distinct credit-driven focus. U.S. Public Finance Credit Risk Management will be led by Peter J. Cain; Bob R. Bose and Rick Persaud will co-head Structured and International Finance. All three individuals will report directly to Mr. Wallis. After many years of excellent service, William T. McKinnon, who previously headed Credit Risk Management, has retired from the Firm.

Michael A. Callen, Chairman and Chief Executive Officer, commented, “I am pleased that David agreed to accept this challenge. I view this as an opportunity to adjust our organizational structure to meet the changing dynamics in the credit landscape. On behalf of the Board and senior management team of Ambac, I would like to thank Bill for his many years of excellent service to the Company. We wish him well in his retirement.”

Mr. Wallis joined Ambac in 1996 in Ambac’s London office where he helped develop and lead Ambac’s European Structured Finance and Securitization business. In 2003, he transferred to Ambac’s New York headquarters where he was a member of the Credit Risk Management team. He was promoted to Senior Managing Director and Head of Portfolio and Market Risk Management in 2005. Prior to joining Ambac in 1996, he was an investment banker at NatWest in the Debt Structuring Group, having previously held positions in Japan and in Strategic Planning. Mr. Wallis holds an Economics degree from Downing College, Cambridge and an MBA from the City University Business School in London.

Ambac also announces the appointment of a new head of Investor Relations. Vandana Sharma will take over responsibilities from Peter R. Poillon, who is leaving Ambac to pursue other opportunities. Ms. Sharma joined Ambac’s Structured Credit Group in 2007. She came to Ambac from Barclays where she was responsible for allocating counterparty limits and approving counterparty exposures for all monolines. Prior to Barclays, Ms. Sharma worked at S&P in both the Insurance and CDO Groups. At S&P, Vandana was responsible for analyzing the CDO exposures for the monolines. Paul Burke will continue handle Fixed Income Investor Relations.