"I feel like I'm getting on a train that's going full speed," said Harold M. Williams yesterday, a day after being confirmed by the Senate as the new chairman of he Securities and Exchange Commission.

In an informal meeting with reporters, Williams skillfully avoided particulars about his plans for the commission.

He said he will return to Calfornia next week to wind up his personal and business affairs. He will resign as dean of the graduate school of management at the University of California at Los Angeles and from numerous boards of directors.

So soft spoken that he often verges on inaudible, Wiliams said that he brings to "the party a broad perspective which comes from a number of exposures."

Among the "exposures" he ticked off were "economics, political science, accounting, law, corporate management, leadership, and defendant in derivation shareholder suits" as a board member.

Now 49 yers old, Williams graduated Phi Beta Kappa from UCLA when he was only 18. After Harvard Law School and an army tour as a legal officer. Williams began specializing in tax law.

Hired by conglomateur Norton Simon, he became president of Hunt Foods and INdustries, Inc., in 1968, and later, chairman of Norton Simon, Inc.

In 1970, he quit Norton Simon to head up UCLA's then second-rate business school, which has gained national prominence under him.

Williams said he promised President Carter to serve as chairman for the full term of five years, along with two months left over from his predecessor. (If Carter runs again for President and loses, Williams' tenure would, of course, be cut short).

There still remains one vacancy on the five-man commission. Since the commissioners each have one vote on all critial investigative and policy matters, the fifth commissioner (and third Democrat) will have the power of a swing vote.

Williams conceded yesterday that he had "indicated his preferences" for the spot to Carter, but he would not reveal any of the names he suggested. He said he expected the commission seat, which had been vacant since April 2, 1976, when A.A. Sommer Jr. resigned, to be filled "rather quickly."

Wiliams said he was "somewhat surprised at the magnitude" of he reported bribery by corporate officials. "I have trouble accepting the concept that you do what you need to do to keep competitive," he said.

He echoed other SEC officials and legislators in differentiating between "outright bribes" and less serious "facilitating payments."

A board member of several corporation, Williams said:

"The concept of outside audit committees is potentially one of the most important in a long time."

Outside audit committees is potentially one of the most important in a long time."

Outside audit committees, which have gained impetus from revelations of corporate bribery, are meant to insulate a company's outside accountants from being pressured by its executives.

The New York Stock Exchange soon will mke audit committees, made up of directors from outside the company, mandatory for member companies.

As for personnel changes on top at the SEC, Willams said he does not expect to do anything drastic in the near future.

"Don't forget," he said, "the commission has been assessed by those who know as the best in Washington."