The sudden departure of Treasury Secretary Paul H. O'Neill gives President Bush added impetus to name a new Securities and Exchange Commission chairman to avoid having two of the administration's key economic posts simultaneously rudderless, government and financial industry sources said yesterday.

The White House goal of naming someone quickly, perhaps by the end of next week, to replace outgoing SEC Chairman Harvey L. Pitt is likely to stay on track, the sources said. But there was no clear front-runner apparent to Wall Street insiders.

O'Neill has been heavily involved in the SEC selection process.

Wall Street officials differ over whether O'Neill's departure will help or hinder the possible SEC nomination of Peter R. Fisher, undersecretary of domestic finance in the Treasury Department. Fisher has said he doesn't want the job of SEC chairman, but he remains on the White House's short list of possible nominees, sources said.

Some financial industry sources said White House officials may be less inclined to pick Fisher for the SEC post because they will want to cause as little further disruption to the department as possible after O'Neill leaves. But others say the White House could just as easily decide that O'Neill's replacement will want to pick his own undersecretary of domestic finance, making this a great time to ask Fisher to move to the SEC.

The search for an SEC chairman began early last month, when Pitt resigned under pressure because of criticism over how he handled the creation of a national accounting oversight board.

Other candidates who continue to be mentioned as possible replacements are T. Timothy Ryan Jr., an executive at J.P. Morgan Chase & Co., who ran the agency that regulated the savings-and-loan industry at the end of the previous Bush administration; Stephen L. Hammerman, who resigned as chief counsel of Merrill Lynch & Co. in February to become the top legal adviser to the New York City police commissioner; and Robert R. Glauber, head of NASD, a self-regulatory body for the securities industry. Glauber helped the government manage the savings-and-loan crisis in the 1980s.

Another person being considered by the White House is an attorney on the West Coast, though sources who said they know who she is would not identify her. Others speculated that it might be former SEC commissioner Aulana L. Peters, an attorney in the Los Angeles office of Gibson, Dunn & Crutcher LLP. She could not be reached for comment yesterday.

A White House spokesman would not comment.

The White House's struggle to revamp its economic team comes at a difficult time for the nation's securities markets, which are facing widespread investor mistrust after a series of accounting and corporate scandals in the past year.

Peter R. Fisher, a Treasury undersecretary, is a possible nominee for SEC chairman.