National Manufacturing Co., Sterling, Ill., might shift some of its active domestic large-cap equity holdings to passive management, said Bob Jones, assistant treasurer. The $60 million pension plan has active large-cap growth, value and core managers; Mr. Jones declined to identify the firms. The amount to be shifted to indexing, likely benchmarked to the S&P 500, has not been determined, he said. A decision about whether to proceed with the change is expected "reasonably soon," he said. Smith Barney is assisting.