It's official:  MF Global filed for bankruptcy protection for its U.S. parent company this morning.  It's the first American financial casualty of the European debt crisis. In the Chapter 11 filing in Federal Bankruptcy Court in Manhattan, the firm listed assets of between $100mn and $500mn and liabilities in excess of $1bn.  JPMorgan is identified as the biggest creditor, with a claim of $1.2bn.  Skadden, Arps, Slate, Meagher & Flom is representing MF Global in the bankruptcy proceedings. As part of the bankruptcy, Interactive Brokers had been expected to commit to buy the assets of MF Global.  That would be somewhat similar to what Lehman Brothers did in 2008, when its parent filed for bankruptcy but Barclays bought some of the assets.  However, people briefed on the matter said it's just about certain that the deal is dead. Earlier today, the NY Fed suspended trading of MF Global. [Dealbook, 10/31/11]