X0202 4 2003-05-04 0000874501 AMBAC FINANCIAL GROUP INC ABK 0001194126 CALLEN MICHAEL A AMBAC FINANCIAL GROUP, INC. ONE STATE STREET PLAZA NEW YORK NY 10004 1 0 0 0 Common Stock 2004-05-04 4 A 0 865 69.38 A 26110 D Director Stock Units ("DSUs") were granted under the 1997 Non-Employee Directors Equity Plan, as amended. The number of DSUs was determined based on the average of the high and low selling price of the Issuer's common stock on May 4, 2004. Anne G. Gill, Attorney-in-fact for Michael A. Callen 2004-05-05