================================================================================ 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): December 4, 2001 (December 3, 2001) AMBAC FINANCIAL GROUP, INC. (Exact name of Registrant as specified in its charter) Delaware 1-10777 13-3621676 (State of incorporation) (Commission file number) (I.R.S. employer identification no.) One State Street Plaza 10004 New York, New York (Zip code) (Address of principal executive offices) (212) 668-0340 (Registrant's telephone number, including area code) Page 1 of 5 Pages ================================================================================ Index to Exhibits on Page 4 Item 5. Other Events On December 3, 2001, Ambac Financial Group, Inc. (the "Registrant") issued a press release announcing that its principal operating subsidiary, Ambac Assurance Corporation, will replace a portion of its bank line capital support with an innovative capital markets structure. Through the new structure, Ambac Assurance acquired an unconditional and perpetual put option on $400 million of its preferred stock from a high quality asset-backed trust. The issue was privately placed. Exhibit 99.07 is a copy of the press release and is incorporated herein by reference. Item 7. Financial Statements, Pro Forma Financial Information and Exhibits (c) Exhibits. Exhibit Number Item -------------- ---- 99.07 Press release announcing on December 3, 2001 that its principal operating subsidiary, Ambac Assurance Corporation, will replace a portion of its bank line capital support with an innovative capital markets structure. Page 2 of 5 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. Ambac Financial Group, Inc. (Registrant) Dated: December 4, 2001 By: /s/Frank J. Bivona -------------------------------------- Frank J. Bivona Vice Chairman and Chief Financial Officer Page 3 of 5 INDEX TO EXHIBITS ----------------- Exhibit Number Description of Exhibit - ------- ---------------------- 99.07 Press release announcing on December 3, 2001 that its principal operating subsidiary, Ambac Assurance Corporation, will replace a portion of its bank line capital support with an innovative capital markets structure. Page 4 of 5