Goldman Sachs Group Inc., practicing its high-tech preaching, bought an electronic stock-trading company, Hull Group Inc., in the investment bank's first acquisition since going public in May.

The $531 million purchase will be paid for with stock, options and cash. Though details have not been completed, according to David Viniar, Goldman's chief financial officer, "we've made it clear that virtually every Hull employee will receive stock."

Hull is a Chicago-based company that buys and sells futures, options and stocks electronically on 28 exchanges in nine countries. It has 250 employees, including software developers and traders.

Analysts viewed the deal as a minor event, with a larger context -- Goldman's push to become a leader in technology. The company, which has been a major underwriter of initial public stock offerings of technology companies, recently purchased a 22 percent stake in Wit Capital Corp., an online investment company that has applied to become a stock exchange.

Increasingly, trading is shifting from the floors of exchanges to computers. Revenue from electronic trading grew to 67 percent of Hull's total revenue last year, up from 12.5 percent four years earlier.

Goldman, with Merrill Lynch & Co. and Bernard L. Madoff Investment Securities, created a new electronic auction market for stocks last month. The joint venture, called Primex Trading, is due to begin electronic trading in mid-2000.

"The leaders of our firm are pushing us as an organization to be at the front edge of technology," said Bob Steel, co-head of equities. "Hull greatly complements that ambition."