NEW YORK, Jan. 18, 2008 (PRIME NEWSWIRE) -- Stull, Stull & Brody today announced that it has commenced an investigation relating to the 401(k) defined contribution retirement plans of Ambac Financial Group, Inc. ("Ambac" or the "Company") (NYSE:ABK). Among other things, Stull, Stull & Brody is investigating whether fiduciaries of the Ambac 401(k) plans may have violated the Employee Retirement Income Security Act of 1974 ("ERISA") by failing to disclose the Company's true operating condition to participants and beneficiaries of the plans (including by failing to maintain proper standards and controls relating to the insuring of collateralized debt obligations), by offering Ambac stock as an investment option under the plans when it was not prudent to do so, and/or by allowing an imprudent overconcentration of Company stock in the Company's 401(k) plans.

If you held Ambac stock in an individual account under any of the Company's 401(k) plans at any time since January 1, 2006 you may, if you wish, consult with a representative of Stull, Stull & Brody at no cost or obligation. The contact information for Stull, Stull & Brody is as follows:

 Fax:    (212) 490-2022
 Toll Free Number: 1-800-337-4983
 (Edwin J. Mills, Esq., Tzivia Brody, Esq., or Michael J. Klein, Esq.)

 Mail:  Stull, Stull & Brody
        6 East 45th Street
        New York, NY 10017

Stull, Stull & Brody has extensive experience in protecting the rights of 401(k) plan participants and beneficiaries and shareholders of public companies. Stull, Stull & Brody is presently representing classes of 401(k) plan participants in many class action cases throughout the country. Stull, Stull & Brody maintains offices in New York and Los Angeles.

Stull, Stull & Brody