A key Securities and Exchange Commission official has said he will remain on the job until his replacement is confirmed by the Senate to help ensure the agency remains at an even political balance.

Democratic Commissioner Harvey J. Goldschmid had previously announced he would leave early this summer, taking a short break before resuming his post at Columbia University's law school in the fall. But after prodding from Sen. Charles E. Schumer (D-N.Y.) late Wednesday, Goldschmid told the lawmaker that he is prepared to stay through August, or perhaps even longer if necessary.

Word of Goldschmid's change in plans comes two weeks after President Bush said he would nominate Rep. Christopher Cox (R-Calif.) to be the agency's new chairman. Cox would replace outgoing chairman William H. Donaldson, who has said he will depart June 30. Cox's nomination requires the approval of the Senate, as do nominations for the agency's two Democratic slots -- both of which will be coming open.

Senate Democrats have urged the White House to nominate Annette L. Nazareth, director of the agency's division of market regulation, to fill the Goldschmid vacancy. They also asked for Democrat Roel C. Campos, whose tenure expired earlier this month, to be nominated to serve another five-year stint. Under current rules, Campos can remain at the SEC for up to 18 months after his term has ended. The White House has not acted on the recommendations. Spokeswoman Erin Healy said she would not speculate on the timing of personnel announcements and noted that Campos and Goldschmid remain at the agency under holdover provisions.

Schumer, who has aggressively backed Nazareth's candidacy, is lobbying for the administration to bring forth all three nominees in a package deal.

"Senator Schumer is pushing hard for a full commission," his spokesman Israel Klein said. "Ultimately we want to see the slots filled before the end of the summer."

The Senate Banking Committee has not received paperwork on any of the three, a spokesman said yesterday. Andrew Gray, a spokesman for the panel's chairman, Sen. Richard C. Shelby (R-Ala.), said it is up to the White House to determine how and in what order nominations are sent to the panel. "Regardless of party or position, we try to move quickly on all nominations," Gray said.

In recent weeks, Goldschmid has publicly talked about the "delicate balance" at the agency, which has passed several controversial rules with 3 to 2 votes.

Donaldson, 74, frequently cast his vote with the SEC's two Democrats, sometimes frustrating business groups and members of the Cabinet. He sided with Democrats in mandating stricter oversight for mutual funds and hedge funds and in imposing financial penalties on companies whose executives directed accounting frauds.

The agency's two Republican commissioners, Paul S. Atkins and Cynthia A. Glassman, have objected publicly to large fines against companies. Instead, they favor penalizing individuals caught cooking the books. They opposed a recent $100 million penalty against health care company HealthSouth Corp., for instance, according to sources briefed on the matter who spoke on the condition of anonymity because internal SEC deliberations are secret.