Karsten Mahlmann to Head Office in London

Former Chicago Board of Trade Chairman Karsten Mahlmann has accepted a job as chief of the London office of Rosenthal-Collins Group, a Chicago-based futures brokerage.

Mahlmann resigned as leader of the world’s largest commodities exchange in August amid problems at Stotler & Co., the now-defunct brokerage he headed.

Rosenthal-Collins is run by Leslie Rosenthal, a political opponent of Mahlmann who opposed him in last year’s election for exchange chairmanship.

Rosenthal and Mahlmann said Monday that their political differences have never interfered with their friendship.

“The poor guy’s been punished enough,” Rosenthal said. “His life savings were tied up in a firm that went down the drain. At 53, he’s starting over again.”