X0303 4 2010-05-21 0000874501 AMBAC FINANCIAL GROUP INC ABK 0001042563 THEOBALD THOMAS C AMBAC FINANCIAL GROUP, INC. ONE STATE STREET PLAZA NEW YORK NY 10004 1 0 0 0 Common Stock 2010-05-21 4 S 0 12000 .98 D 61750 D Common Stock 2010-05-21 4 S 0 1500 1.01 D 0 I As trustee for Daniel F. Theobald Common Stock 2010-05-21 4 S 0 1500 1.01 D 0 I By Spouse as custodian for Fiona M. Theobald These shares are held in a trust for the benefit of the Thomas Theobald's son. Thomas Theobald is the trustee. Thomas Theobald disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Thomas Theobald is the beneficial owner of these securities for purposes of Section 16 or for any other purpose. These shares are held in a trust for the benefit of the Thomas Theobald's daughter. Thomas Theobald's spouse is the trustee. Thomas Theobald disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Thomas Theobald is the beneficial owner of these securities for purposes of Section 16 or for any other purpose. Patricia LoCascio, Attorney in Fact for Thomas C. Theobald 2010-05-24