Ambac Financial Group Files for Chapter 11 Bankruptcy

``Ambac Financial Group Inc., a holding company for the bond insurer being restructured by state regulators in Wisconsin, filed for bankruptcy protection to reschedule payments on more than $1 billion in bonds and other claims. The petition for Chapter 11 protection filed in Manhattan today listed assets of $394.5 million and liabilities of $1.68 billion. The Vanguard Group Inc. was listed as the largest shareholder, with 5.46 percent of the company’s stock.''