GENEVA, NOV. 17 -- Top U.S. and Soviet negotiators today ended three days of intensive talks aimed at resolving lingering differences over an intermediate-range missile treaty, and senior officials on both sides said they expected the pact to be ready for signing at the December summit meeting between President Reagan and Soviet leader Mikhail Gorbachev.

Chief Soviet negotiator Yuli Vorontsov said after meeting with his U.S. counterpart, Max Kampelman, that the treaty text should be completed by next Monday. U.S. officials said they were unaware that such a deadline had been fixed.

A senior U.S. official said there had been "substantial progress" in the talks here and that he had "no reason to doubt" that the treaty would be completed in time to be signed by Reagan and Gorbachev when they meet in Washington Dec. 7-10.

The meetings here, which began Sunday evening, yielded "helpful movement" in resolving the timing and phasing of reductions in missile forces, another U.S. official said.

Nevertheless, several U.S. officials cautioned that a substantial amount of work on verification issues remained to be completed before the treaty would be ready. One suggested that the pact would not be completed as scheduled unless the Soviets soon showed greater "flexibility" on measures sought by the United States to guard against cheating.

"There's quite a bit of work there. I'm not about to say that it's not doable. We're working very much against the deadline given to us," another U.S. official said.

{In Washington, White House spokesman Marlin Fitzwater said the problems holding up the treaty are "serious in a technical and arms control sense" but do not threaten the summit schedule. Another White House official said it was "absurd" to think the problems could delay the summit and described the delays as part of the "end-game" bargaining process. "We'll get it done," he said.}

The Intermediate Nuclear Forces (INF) treaty would provide for dismantling all of the superpowers' missiles with ranges of between 300 and 3,500 miles within three years. Most of the missiles are based in Europe.

U.S. officials said they doubt that it will be necessary for Secretary of State George P. Shultz and Soviet Foreign Minister Eduard Shevardnadze to meet again before the summit to settle the remaining disagreements. They already have met three times this autumn to discuss the issue.

U.S. officials complained that the Soviets were delaying the process of handing over a critically important package of data giving the location of all Soviet missiles to be dismantled under the treaty. Without that data, it was impossible to put the final touches on verification provisions, they said.

Comparable data on U.S. missiles is ready to be given to the Soviets in an exchange as soon as the Soviets are ready. The Soviets have been promising to provide the information since before last month's talks in Moscow between Shultz and Shevardnadze, U.S. officials said.

"They keep telling us it's going to come tomorrow. We still haven't got it," a U.S. official said.

Another U.S. official, however, said that the delay in receiving the data "was not a serious problem." The Soviets had promised to hand it over by Wednesday, he said. "They know they have to give it to us. They're going to give it to us."

The Soviets said that the delay was due to "technical reasons," the official said. "They're having trouble getting it together."

The two sides also have disagreed over how to monitor sites where it is suspected that the other side is manufacturing or storing missiles that are to be banned under the agreement, U.S. officials said.

The Americans want the right for permanent, on-site monitoring of facilities where Soviet SS25 missiles are produced, a U.S. official said.

The SS25 is a long-range missile, and therefore is not covered by the INF treaty. But the Americans contend that the first stage of the SS25 is so similar to the intermediate-range SS20, which is to be dismantled under the pact, that it is necessary to monitor a plant where SS25 missiles are produced to make sure the Soviets are not producing SS20s there as well.

Vorontsov, in an interview with Soviet television before his last meeting with Kampelman today, charged that the American demand was "artificial."

He also called on the Americans to agree to more extensive measures for physically dismantling cruise missiles. The Americans have proposed to salvage the missiles' warheads, guidance systems and rocket motors, while destroying only the casings and wings, Vorontsov said. "This is, of course, not serious, and we shall press for a real destruction of these missiles."

A U.S. official did not dispute Vorontsov's description of the U.S. position. But he said that the U.S. stance had been well-known to the Soviets for months, and suggested that the Soviets had raised the objection "at the last minute" in an effort to wrest concessions from the Americans.

The Americans are resisting Soviet demands for what the U.S. side considers to be excessively intrusive inspection rights at U.S. military facilities in Western Europe, a U.S. official said.