The Bush administration, attempting to repeat the close U.S.-Soviet cooperation that helped end the fighting in Nicaragua, has enlisted Moscow's help for a negotiated solution to the decade-long civil war in El Salvador, administration officials said in recent interviews.

With active prodding from Washington, Soviet and Salvadoran officials have held several meetings, and President Bush raised the subject with Soviet Foreign Minister Eduard Shevardnadze earlier this month in New York, officials said.

Administration officials said they hope the contacts will lead to establishment of diplomatic relations between Moscow and San Salvador, a move that would be a major setback for leftist rebels fighting the Salvadoran government. The boost such ties would give the Salvadoran government could serve as a counterbalance should Congressional efforts succeed in cutting in half next year's military aid proposal for El Salvador. A Senate vote on the aid proposal is likely Thursday.

Earlier this year Shevardnadze said the Soviet Union intended to support efforts to resolve conflicts in Central America. The Soviets last year helped persuade the Sandinistas, their own aid clients in Nicaragua, to call the elections that were won by the U.S.-backed opposition candidate.

In a more recent reflection of its newly cooperative attitude, Moscow said earlier this month it was opening formal relations with Honduras, another longtime U.S. ally in the region. But the Soviets are moving cautiously on El Salvador. A Soviet Foreign Ministry official said in Moscow yesterday that "there are no plans to establish diplomatic relations with El Salvador at this time."

Moscow and Washington have been on opposite sides of El Salvador's civil war since it began in 1980.

Soviet ties to the rebel Farabundo Marti National Liberation Front (FMLN) have been less strong than the full-fledged alliance with the Sandinistas, whose government depended on massive Soviet aid.

The administration does not believe the Soviets provide direct financial or military assistance to FMLN rebels, but Moscow has maintained close ties to at least one of the five FMLN factions, and provided diplomatic and ideological support for the FMLN over the years.

But officials said the administration hopes the Soviets will try to persuade Cuba, which the United States charges is the principal provider of military assistance and financial support to the FMLN, to support efforts toward a negotiated settlement. Those efforts now are taking place principally at the United Nations, where talks between the Salvadoran government and the rebels have recently bogged down because of what the administration charges is FMLN intransigence.

The first high-level Salvadoran-Soviet contact was a July 14 meeting at the Salvadoran Embassy in Washington, set up by Bernard W. Aronson, assistant secretary of state for Inter-American Affairs, between Aronson's Soviet counterpart, Yuri Pavlov, and Salvadoran Foreign Minister Manuel Pacas, according to Salvadoran Ambassador Miguel A. Salaverria.

Pavlov's deputy, Jan Burliay, met in San Salvador on Aug. 25 with Salvadoran President Alfredo Cristiani, the first visit of a Soviet official to El Salvador. According to U.S. and Salvadoran officials, Burliay said the Soviet Union might be willing for the first time to open formal diplomatic relations with El Salvador and would be willing to intercede with Cuba to promote negotiations.

Aronson, who coordinated diplomatic efforts with the Soviets on Nicaragua, met with Pavlov in Moscow in mid-September to further urge the Soviets to improve relations with the Salvadoran government, and to discuss the Salvadoran situation with the Cubans, sources said.

Bush underscored U.S. concern in his meeting with Shevardnadze, officials said. Shevardnadze said he wanted to work on it further with Secretary of State James A. Baker III before Bush and Soviet President Mikhail Gorbachev got involved.

At the United Nations, Aronson and U.S. Ambassador Thomas R. Pickering held what one source called a "tense" meeting with U.N. negotiators, in which they said the FMLN was blocking negotiations. The rebels have demanded that hundreds of military officials alleged to be major human rights violators in the Salvadoran armed forces be purged before a formal cease-fire and that some of those responsible for the worst atrocities, such as the murders of six Jesuit priests in November, be prosecuted.

The U.N. officials, while agreeing that something needs to be done to jump-start the stalled talks, did not agree the negotiations deadlock was solely the fault of the FMLN, sources said.

Staff writer Michael Dobbs contributed to this report from Moscow.