CalMat filed suit against Industrial Equity (Pacific) and IEP president Ronald Langley, who is also a director of CalMat, charging that IEP used non-public information in increasing its stake in the Los Angeles construction company . . . Shamrock Capital L.P., a limited partnership led by Shamrock Holdings of Burbank, said it has completed the sale of Central Soya Co. to Ferruzzi Agricola Group of Italy in a deal valued at about $370 million . . . Culver City-based Rexon Inc. said its directors authorized the repurchase of up to $15 million of its common shares from time to time on NASDAQ . . . Santa Barbara-based Mentor Corp. said its board authorized the purchase of up to 2 million shares of its common stock . . . Taco Bell Corp., a unit of Pepsico Inc., said it raised its stake in San Mateo-based Calny Inc. to 27.9% of the common shares outstanding . . . IC Industries of Chicago approved a plan to buy back as much as $1 billion in common stock, cut costs by $50 million and expand more heavily into consumer goods and services companies . . . The Federal Reserve said the average yield for one-year T-bills, the most popular index for making changes in adjustable rate home mortgages, rose to 8.33% last week after averaging 8.10% the week before.