UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 12b-25

NOTIFICATION OF LATE FILING

(Check One):	¨  Form 10-K     ¨  Form 20-F     ¨  Form 11-K     x  Form 10-Q ¨  Form 10-D     ¨  Form N-SAR     ¨  Form N-CSR
	For Period Ended: September 30, 2010
	¨  Transition Report on Form 10-K
	¨  Transition Report on Form 20-F
	¨  Transition Report on Form 11-K
	¨  Transition Report on Form 10-Q
	¨  Transition Report on Form N-SAR
	For the Transition Period Ended:

Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I — REGISTRANT INFORMATION

Ambac Financial Group, Inc.

Full name of registrant

Former name if applicable

One State Street Plaza

Address of principal executive office (street and number)

New York, New York 10004

City, state and zip code

PART II — RULES 12b-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

x	(a)	The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense;
	(b)	The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and
	(c)	The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

PART III — NARRATIVE

State below in reasonable detail the reasons why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

On November 8, 2010, the Company filed a voluntary petition for relief under chapter 11 of title 11 of the United States Bankruptcy Code in the United States Bankruptcy Court for the Southern District of New York. The Company is currently evaluating the need for additional and/or modification of disclosure in its Form 10-Q as a result of such filing. As a result, the Company is unable to file its Form 10-Q for the nine months ended September 30, 2010 by the prescribed due date without unreasonable effort or expense.

PART IV — OTHER INFORMATION

(1) Name and telephone number of person to contact in regard to this notification

Robert B. Eisman	212	668-0340
(Name)	(Area Code)	(Telephone Number)

(2) Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If answer is no, identify report(s).    x  Yes    ¨  No

(3) Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?    x  Yes    ¨  No

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

The registrant does not anticipate any significant change in the results of operations from that reported by the registrant on November 9, 2010 in a press release announcing its operating results for the quarter ended September 30, 2010. The full text of the press release was furnished on a Current Report on Form 8-K, which was furnished to the Securities and Exchange Commission on November 10, 2010.

Ambac Financial Group, Inc.

(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

Date:	November 10, 2010	By:	/s/ Robert B. Eisman
		Name:	Robert B. Eisman
		Title:	Senior Managing Director and Chief Accounting Officer