A former savings and loan regulator testified under oath yesterday that officials in Washington ordered him to wait for two months in 1988 -- until after Election Day -- before closing a failing Colorado thrift where President Bush's son Neil had been a director.

The delay was ordered despite a request by field supervisors that action should be taken in October, said Kermit Mowbray, former president of the Federal Home Loan Bank in Topeka, Kan. He testified before the House Banking Committee, which is investigating the failure of the Denver-based Silverado Banking, Savings and Loan Association. Mowbray was the top regional regulator for thrifts in a four-state region that includes Colorado.

Mowbray, who was subpoenaed to testify by the committee after he refused to appear voluntarily, said he cannot remember who at the federal thrift regulatory agency in Washington placed the telephone call giving the order on Silverado.

"I just don't recall," he told reporters during a break in the hearing.

Mowbray submitted a formal recommendation that Silverado be placed into receivership one day after George Bush was elected president, and the thrift was seized by federal regulators on Dec. 9, 1988.

The thrift's failure is expected to cost taxpayers $1 billion, a sum that congressmen from both parties say could have been substantially reduced if officials in Topeka and in Washington had taken action in 1986 and 1987, when its problems first became known.

While Mowbray was being questioned, congressmen released a copy of a document prepared last December by the Office of Thrift Supervision (OTS), the federal savings and loan regulatory agency, detailing previously secret charges that Neil Bush and several other Silverado officials and directors violated their financial responsibilities to the thrift and contributed to its failure.

In the document prepared by OTS, thrift regulators recommended that Bush and the other Silverado executives be barred from the banking industry. The others agreed to the ban earlier this year.

Bush challenged the allegations against him, however, and OTS officials agreed to alter the charges and lower the recommended penalty to making him agree that he will "cease and desist" from the kind of activities he engaged in at Silverado. But Bush refused to accept the lesser penalty as well, and the matter is now being sorted out in an administrative proceeding.

In yesterday's testimony, Mowbray said he believed that regulators, including himself, would have been wiser to act sooner on Silverado, but he denied the delay was prompted by the presence of Neil Bush, who became a director of the thrift in the summer of 1985 and resigned in the summer of 1988, shortly before his father was nominated as the GOP candidate for president.

''I have never met Neil Bush and I never received any official or unofficial inquiries on his behalf,'' Mowbray said.

Shortly after Silverado was closed, Mowbray was fired from his job as regional thrift supervisor by M. Danny Wall, then the nation's top federal thrift regulator.

"I was the fall guy," Mowbray said of Wall's decision. Democrats have challenged Wall's stewardship as head of the agency that regulated thrifts, now OTS but then called the Federal Home Loan Bank Board, saying Wall acted politically and unwisely in delaying action on several of the costliest thrift failures.

On Oct. 21, 1988, the Colorado thrift commissioner informed Mowbray that the state would move to close Silverado, a state-chartered and federally insured thrift, by the end of the month. Mowbray relayed the information to officials in Washington, who three days later, on Oct. 24, 1988, asked that action be delayed for two months. Mowbray relayed Washington's request to the Colorado commissioner by letter.

Mowbray said Wall's decision to fire him was prompted in part by accusations from officials in Washington who blamed Mowbray and his staff for "misleading" them about Silverado, a charge Mowbray denied.

"My staff, at my direction, had prepared information which I presented to ... Wall indicating that my staff had fully informed" officials in Washington of the thrift's problems, Mowbray told the banking committee. "We supply the information. They {in Washington} determine what will happen on what day."

Members of the House Banking Committee were interested in the marching orders Mowbray said he received from Washington, but many expressed equal dissatisfaction with his performance, including his failure to take stronger action soon after a troubling July 1987 examination of Silverado.

Neil Bush, 34, who voluntarily appeared before the same panel on May 24, has denied any wrongdoing in connection with Silverado. The panel has been probing whether his business interests in Colorado conflicted with his role as a director of the thrift. He has called allegations of conflict of interest ''frivolous.''

William Fulwider, a spokesman for the OTS, said yesterday that a cease-and-desist order had been issued against Bush by the OTS, which announced in January its intention to do so. Fulwider said the document released by congressmen yesterday was a draft, and that after it was written and OTS officials had weighed Bush's objections to the charges in it, the OTS agreed that the agency lacked sufficient evidence to support barring Bush from the industry. That is when the agency adopted the less serious cease-and-desist order against the president's son.

The document outlines three areas where thrift regulators object to Neil Bush's actions.

Bush failed to inform the other directors in 1987 that one of his business partners, developer Kenneth Good, had committed himself to invest $3.1 million in Bush's oil exploration company, according to the document. At the same time, it said, the directors were being told that Good probably would be able to repay only $3 million of the $11 million in loans and other obligations he had to Silverado. The board agreed to the lower payment.

At the time of the board meeting, "Bush failed to disclose that Good was going to contribute $3.1 million" to a company jointly owned by Good and Bush, JNB Exploration Co., the document says. The $3.1 million was to repay Bush for the 80 percent stake in JNB that Bush had agreed to give Good on September 1987.

Under the September agreement, Good had to pay the $3.1 million within 18 months or forfeit the 80 percent ownership in JNB, according to Bush's lawyer, James E. Nesland. Because Good was not obligated to pay the $3.1 million and could elect to simply return his share in the company, the arrangement was an "option" and not a concrete obligation that Bush should have disclosed, the lawyer said.

Bush sought to get a $900,000 letter of credit from Silverado for Good that he would use to vouch for his financial stability to Argentina, where companies owned by Bush and Good were trying to win the right to explore for oil.

Bush's lawyer said the request for the letter was never "consummated," even though Silverado's board of directors approved it on Nov. 24, 1986. Good gave a personal guarantee instead to win the contract, according to Nesland.

According to a letter Bush wrote on Nov. 5, 1986, to a Silverado executive, however, Bush said that Good had already presented the $900,000 line of credit to the Argentine government.

Bush, as a director, voted to grant loans from Silverado to one of his former business partners, William Walters, or to companies he controlled, the document says.

Bush contends his relationship with Walters predated his arrival at Silverado and therefore posed no conflicts.