Mahlmann Files for Bankruptcy: Karsten Mahlmann, the former Chicago Board of Trade chairman facing extensive legal battles regarding a trading firm he once headed, has declared personal bankruptcy, his attorney said. Court documents show Mahlmann's assets are between $100,000 and $500,000, while his liabilities are between $500,000 and $1 million, said the attorney, Jonathan Backman. Mahlmann headed the Stotler Group trading firm when it was unable to meet CBOT and federal capitalization requirements in July, 1990. The firm filed for bankruptcy the following month. Mahlmann resigned as CBOT chairman Aug. 1, 1990. He now works in London for the Chicago-based brokerage firm Rosenthal-Collins Group.