SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): June 13, 2011 (June 10, 2011)

AMBAC FINANCIAL GROUP, INC.

(Exact name of Registrant as specified in its charter)

One State Street Plaza, New York, New York 10004

(Address of principal executive offices) (Zip Code)

(212) 668-0340

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Item 7.01 Regulation FD Disclosure.

On June 10, 2011, Ambac Assurance Corporation (“Ambac Assurance”), a subsidiary of Ambac Financial Group, Inc. (the “Company”), issued a press release announcing that the Commissioner of Insurance for the State of Wisconsin, acting as Rehabilitator of the Segregated Account of Ambac Assurance Corporation (the “Segregated Account”), has entered into a consulting agreement with Roger A. Peterson, pursuant to which Mr. Peterson has been engaged as a consultant to administer the Segregated Account in the capacity of Special Deputy Commissioner for the Segregated Account. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

The information in Item 7.01 and Exhibit 99.1 of this report is being furnished, not filed, pursuant to Regulation FD. Accordingly, the information in Item 7.01 and Exhibit 99.1 of this report will not be incorporated by reference into any registration statement filed by the Company under the Securities Act of 1933, as amended, unless specifically identified therein as being incorporated therein by reference. The furnishing of the information in this report is not intended to, and does not, constitute a determination or admission by the Company, that the information in this report is material or complete or that investors should consider this information before making an investment decision with respect to any security of the Company or any of its affiliates.

Certain statements in this document and the exhibit are “forward looking statements” within the meaning of the Private Securities Litigation Reform Act. These statements are based on management’s current expectations and are subject to uncertainty and changes in circumstances. Actual results may differ materially from those included in these statements due to a variety of factors. More information about these factors is contained in the Company’s filings with the Securities and Exchange Commission.

Item 9.01 Financial Statements and Exhibits.

99.1 Press release of Ambac Assurance dated June 10, 2011. The press release is furnished and not filed pursuant to Regulation FD.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.