SECURITIES

Kidder Probe Expands: A Kidder, Peabody Group Inc. executive who supervised Joseph Jett, the bond trader fired for allegedly creating false profits that cost the firm millions, is being investigated about his possible involvement, a published report said. The Wall Street Journal said Melvin R. Mullin, head of Kidder’s derivatives operations, is under investigation by an internal committee looking into the Jett affair. Kidder fired Jett in April, charging him with having created $350 million in phony profits from government bond trades to hide actual losses and to raise his pay. The Journal said Mullin, who hired Jett in 1991 and was Jett’s immediate supervisor until early 1993, is being questioned about whether he knew of the alleged scam.