SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

LASSITER PHILLIP B

(Last)

(First)

(Middle)

AMBAC FINANCIAL GROUP, INC.

ONE STATE STREET PLAZA

(Street)

NEW YORK

10004

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
AMBAC FINANCIAL GROUP INC [ ABK ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	Chairman and CEO

3. Date of Earliest Transaction (Month/Day/Year)
10/29/2003

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	10/29/2003		M		62,232	A	$53.48	1,327,056	D
Common Stock	10/29/2003		F		7,144⁽¹⁾	D	$70.43	1,319,912	D
Common Stock	10/29/2003		F		47,254⁽²⁾	D	$70.43	1,272,658	D
Common Stock	10/29/2003		M		112,500⁽³⁾	A	$48.67	1,385,158	D
Common Stock	10/29/2003		F		77,720⁽⁴⁾	D	$70.43	1,307,438	D
Common Stock								2,721⁽⁵⁾	I	Savings Plan Trust
Common Stock								12,000	I	By Spouse

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Employee Stock Option (Right to Buy	$53.48	10/29/2003		M			62,232	10/30/2001	01/28/2004	Common Stock	62,232	$0	0	D
Employee Stock Option (Right to Buy)	$48.67	10/29/2003		M			112,500	05/29/2002⁽⁶⁾	01/22/2008	Common Stock	112,500	$0	112,500	D
Employee Stock Option (Right to Buy)	$70.43	10/29/2003		A		77,720		10/29/2004	01/22/2008	Common Stock	77,720	$0	77,720	D

Explanation of Responses:

1. Shares were withheld pursuant to the exercise of a tax withholding right under the Issuer's 1997 Equity Plan as amended.

2. Shares were used to pay for the option exercise price of the shares acquired upon exercise of the employee's stock options.

3. Issuance of shares in excess of shares tendered to pay the exercise price of options was made in the form of Restricted Stock Units (total of 34,780) which vest immeditely and will be settled 1 year after the Reporting Person's retirement date.

4. Shares were used to pay for the option exercise price of shares acquired upon exercise of the employee's stock options.

5. Based on a plan statement as of September 30, 2003.

6. Exercisable as follows: fifty percent of shares at or exceeding $64.00 for 20 consecutive trading days on the NYSE (05/29/2002); fifty percent of shares at or exceeding $78.00 for 20 consecutive trading days on the NYSE and if all or a portion of the shares has not vested by January 22, 2008, then such unvested amount shall vest on January 22, 2008.

Remarks:

	Anne G. Gill, Attorney-in-fact for Phillip B. Lassiter	10/31/2003
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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