Bloomberg.com: Worldwide

Bloomberg.com: Worldwide: "MBIA Inc. and Ambac Financial Group Inc., the two largest bond insurers, may each lose $11.6 billion on guarantees of mortgage-linked debt and other securities, according to hedge fund manager William Ackman.
The losses were calculated using a model supplied by an unnamed investment bank, and the findings were sent in a letter to the Securities and Exchange Commission and New York Insurance Superintendent Eric Dinallo. Ackman, a managing partner of Pershing Square Capital Management LP, began questioning MBIA's AAA rating in 2002. He has trades set up that would profit from a decline in the price of the shares and bonds of MBIA and Ambac.
Ackman, 41, stepped up his attack by posting on the Internet a list of asset-backed collateralized debt obligations and other securities guaranteed by MBIA and Ambac that allows others to craft their own loss predictions. Ackman said the unnamed bank provided details on many of the securities, not all of which have been disclosed by the companies.
``Up until this point in time, the market and the regulators have had to rely on the bond insurers and the rating agencies to calculate their own losses in what we deem a self-graded exam,'' Ackman said in a statement preceding release of the letter. ``Now the market will have the opportunity to do its own analysis.''"