The Japanese government said it will spend up to another three months studying whether to permit a hostile takeover bid for Japan's Minebea Co. by a U.S.-British investor group . . . As expected, tin brokers met 4-month-old trading commitments in a special clearing session held by the London Metals Exchange . . . A group led by Oklahoma investor J. A. Frates, which is trying to take over Kaiser Aluminum & Chemical, said it owns or controls about 21.62% of Kaiser's 44.3 million common shares outstanding, up from 20.12%.