EXHIBIT 24.02

                          AMBAC FINANCIAL GROUP, INC.
                                        
                               Power of Attorney
                               -----------------



               KNOW ALL MEN BY THESE PRESENTS that the undersigned director and
     officer of Ambac Financial Group, Inc., a Delaware corporation, hereby
     constitutes and appoints each of Anne G. Gill and Joseph V. Salzano, as his
     true and lawful attorney-in-fact and agent, with full power of
     substitution, for him and in his name, place and stead, in any and all
     capacities, to sign the Annual Report on Form 10-K for the year ended
     December 31, 1998, to be filed with the Securities and Exchange Commission
     and the New York Stock Exchange, and any and all amendments thereto, and
     any and all instruments and documents filed as a part of or in connection
     with the said Form 10-K or amendments thereto, and does hereby grant unto
     each said attorney-in-fact and agent full power and authority to do and
     perform each and every act and thing requisite and necessary to be done in
     and about the premises, as fully to all intents and purposes as he or she
     might or could do in person, hereby ratifying and confirming all that each
     said attorney-in-fact and agent shall do or cause to be done by virtue
     hereof.

               IN WITNESS WHEREOF, the undersigned has subscribed these presents
     as of this 25th day of February, 1999.



                                         /s/ Frank J. Bivona    
                                         -------------------                   
                                         Frank J. Bivona