X0202 4 2005-12-14 0000874501 AMBAC FINANCIAL GROUP INC ABK 0001194144 GENADER ROBERT J AMBAC FINANCIAL GROUP, INC. ONE STATE STREET PLAZA NEW YORK NY 10004 1 1 0 0 President and CEO Common Stock 2005-12-14 4 S 0 100 77.91 D 528774 D Common Stock 2005-12-14 4 S 0 100 77.89 D 528674 D Common Stock 2005-12-14 4 S 0 100 77.97 D 528574 D Common Stock 2005-12-14 4 S 0 2000 77.98 D 526574 D Common Stock 2005-12-14 4 S 0 900 77.99 D 525674 D Common Stock 2005-12-14 4 S 0 1700 78.00 D 523974 D Common Stock 2005-12-14 4 S 0 1500 78.02 D 522474 D Common Stock 2005-12-14 4 S 0 100 78.05 D 522374 D Common Stock 2005-12-14 4 S 0 3200 77.88 D 519174 D Common Stock 2005-12-14 4 S 0 200 78.11 D 518974 D Common Stock 2005-12-14 4 S 0 400 78.08 D 518574 D Common Stock 2005-12-14 4 S 0 100 78.07 D 518474 D Common Stock 2005-12-14 4 S 0 900 78.06 D 517574 D Common Stock 2005-12-14 4 S 0 300 78.09 D 517274 D Common Stock 2005-12-14 4 S 0 400 78.05 D 516874 D Common Stock 2005-12-14 4 S 0 200 78.12 D 516674 D Common Stock 2005-12-14 4 S 0 100 78.15 D 516574 D Common Stock 2005-12-14 4 S 0 100 78.10 D 516474 D Common Stock 2005-12-14 4 S 0 100 78.19 D 516374 D Common Stock 2005-12-14 4 S 0 900 78.13 D 515474 D Common Stock 2005-12-14 4 S 0 800 78.13 D 514674 D Common Stock 2005-12-14 4 S 0 300 78.23 D 514374 D Common Stock 2005-12-14 4 S 0 700 78.21 D 513674 D Common Stock 2005-12-14 4 S 0 800 78.20 D 512874 D Common Stock 2005-12-14 4 S 0 2538 78.18 D 510336 D Common Stock 2922 I Savings Plan Trust Based on a plan statement as of November 30, 2005. Anne Gill Kelly, Attorney in Fact for Robert J. Genader 2005-12-15