U.S. officials are concerned that the Soviet Union may try to end separate Intermediate-range Nuclear Force negotiations as one of the three panels at the Geneva arms talks, according to American sources both here and in Washington.

"We are not going to let that happen," one official said yesterday. Until now, the INF panel has dealt with two sets of highly controversial intermediate-range missiles: the American Pershing II and ground-launched cruise missiles being installed in Western Europe and the Soviet SS20 mobile missiles deployed in the eastern, central and western U.S.S.R.

Under the Soviet arms plan, however, the Pershing IIs and cruise missiles, along with U.S. fighter-bombers based in Europe capable of carrying nuclear weapons, would be placed in the strategic pool of nuclear weapons that is the subject of the strategic, or intercontinental-range, arms reduction panel negotiations.

According to U.S. officials in Washington, the Soviet SS20s are "not at all included" in any part of the new Soviet arms package presented to U.S. negotiators.

Soviet leader Mikhail Gorbachev said today in a speech to French legislators in Paris that, in the Russian proposal, SS20 levels would be the subject of talks between the British and French on one side, and the Soviets on the other.

"They have combined the strategic and INF negotiations," a Reagan administration official said in Washington yesterday. "But the SS20s don't count for us." The Soviets maintain that any weapon that can hit the Soviet homeland is strategic, but that their SS20 missiles do not fit that category because they can only reach Europe and Asia and not the United States.

What effect the Soviet approach will have on continued INF talks may become apparent tomorrow when the INF panel is to meet here at the Soviet Mission. This will be the first session after presentation of the new Soviet arms proposals, originally scheduled for today but postponed yesterday by the Soviets until Friday, apparently to await the Gorbachev speech today.

Ambassador Maynard W. Glitman, head of the U.S. INF negotiators, is expected to seek clarification from the Soviets on how they see the future work of the panel.

The Soviet move could throw a procedural cloud over both the strategic and INF panels, depending on how hard the Moscow negotiators push their new approach.

Although the U.S. delegation has only begun to question the Soviets on the details of the complex proposals, officials said Washington's initial reaction was firmly against including the Pershing II and cruise missiles within the strategic force.

Ironically, the Gorbachev move on the American missiles represented a sharp break with Kremlin policy for the past eight years. The new leader's three predecessors tried mightily but unsuccessfully to prevent deployment of the American missiles.

With this new approach, sources said, the new leadership appears to be coming to grips with that foreign policy failure and saying to Washington that it can have its missiles, but at a price. The price is that they would have to be counted in overall strategic cutbacks. This means that retaining the American warheads on the shorter-range Pershing and cruise missiles in Western Europe, under the Soviet plan, would in effect cut down the number of long-range ICBM warheads based back in the United States.

"We are not ready to pay that price," one official said today.

The panel already has an American proposal before it for a zero-zero treaty that would ban all U.S. and Soviet intermediate-range missiles. It also has an interim U.S. proposal that seeks equal global levels of warheads on the two nations intermediate-range missiles.

The first two rounds of the INF talks have been described by Washington sources as unproductive, with both sides clearly putting their basic efforts into the strategic and space panels. One Reagan administration official involved in arms control matters said, "We expected some sort of linkage, between the strategic and INF weapons, but did not expect them to go as far as they went."

Following the presentation here of the official Soviet proposals, without the SS20s, "We have been waiting for them to drop the other shoe on INF," an official said.

The Soviet argument that American missiles and nuclear-capable fighter-bombers based in Europe should be considered strategic weapons and included in any arms agreement is not a new one. It was first raised in the SALT I discussions in the early 1970s.