ABK Ambac Financial Grp. Common Stock

In connection with the issuance of Equity Units (the “Equity Units”) of Ambac Financial Group, Inc. (the “Company”), Anne Gill Kelly, Esq., Managing Director, Secretary and Assistant General Counsel of the Company, has delivered an opinion, dated March 12, 2008, regarding the legality of the Equity Units. A copy of the opinion is filed as Exhibit 5.4 to this Current Report on Form 8-K and is filed with reference to and is hereby incorporated by reference into the Company’s Registration Statement (the “Original Registration Statement”) on Form S-3 (No. 333-131888) filed by the Company with the Securities and Exchange Commission (the “Commission”) on February 15, 2006, as amended by Post-Effective Amendment No. 1 filed on February 6, 2007 and Post-Effective Amendment No. 2 filed on January 16, 2008 (such Original Registration Statement, as amended, the “Registration Statement”), and as supplemented by the final prospectus supplement related to the Equity Units Offering filed by the Company with the Commission on March 10, 2008, pursuant to Rule 424(b) under the Securities Act (the “Units Prospectus Supplement”).

In connection with the issuance of Equity Units, Wachtell, Lipton, Rosen & Katz, counsel to the Company, has delivered an opinion to the Company regarding certain tax matters. A copy of the opinion is filed as Exhibit 5.5 to this Current Report on Form 8-K and is filed with reference to and is hereby incorporated by reference into the Registration Statement.