Union Carbide Corp. has filed suit against...

Union Carbide Corp. has filed suit against seven Japanese companies, claiming that they manipulated the price of polysilicon, a key material used to make silicon wafers for the computer industry. The suit, filed in U.S. District Court in San Francisco, asks for an order prohibiting the seven from fixing prices of polysilicon and controlling its export to Japan. It seeks damages for the losses that Danbury, Conn.-based Union Carbide suffered as a result of the alleged conspiracy. The defendants are Komatsu Electronic Metals Co.; its parent firm, Komatsu Ltd.; Mitsubishi Metal Co.; Mitsubishi subsidiary Nippon Silicon Co.; Osaka Titanium Co.; Shinetsu Handotai Co., and Tokuyama Soda Co.