Paul H. Nitze, the United States' most experienced arms control negotiator, appears to be the leading candidate to become a special envoy for follow-up talks after Secretary of State George P. Shultz and Soviet Foreign Minister Andrei A. Gromyko meet on arms control in Geneva, administration sources said yesterday.

The selection of a special envoy will be one of the priorities when President Reagan meets with his top advisers next week to begin mapping U.S. strategy for the Jan. 7-8 Geneva meeting.

Sources said the administration also will consider whether to approach the new talks, which cover three distinct areas of arms control, under a single umbrella or separately.

The Geneva sessions, announced by the two governments on Thursday, are expected to set an agenda for further talks. Such talks would likely be conducted below the Shultz-Gromyko level to establish a framework and site for the promised new arms-control negotiations. These would encompass not only talks on strategic and intermediate-range nuclear weapons, which have been broken off since last year, but also on military space systems.

Two alternatives that sources said were under study within the administration are a single negotiation with three separate working groups and three different negotiations, each with its own chief negotiator.

The complexities are expected to be too great to be resolved in the two days allotted for the Shultz-Gromyko talks. That is what has led to the idea of a special U.S. negotiator able to work across the broad arms-control agenda and ensure that the three distinct types of weapons systems are dealt with in a rational and effective negotiating framework.

The sources said that many senior administration officials, particularly those regarded as moderates, are leaning toward the choice of Nitze, who was chief U.S. negotiator in the intermediate-range missile talks in Geneva that were broken off by the Soviets a year ago.

These sources said that Nitze appears to best fill the White House's "job description" for special envoy. The requirements are that he be knowledgeable about arms control, have bipartisan support and be experienced in dealing with the Soviets. A possible hitch is that appointment of Nitze or retired general Brent Scowcroft, who also has figured in speculation about the post, is seen by conservatives as an attempt to circumvent hard-liners within the administration such as Defense Secretary Caspar W. Weinberger and his arms control deputy, Richard N. Perle.

This is not the first time Nitze, 77, has been considered for such a post. After the Soviets walked out of both the strategic and intermediate-range talks in Geneva last year, moderates attempted to have Nitze made overall supervisor of combined U.S. arms control efforts. That move failed because Reagan refused to choose between him and retired general Edward L. Rowny, who headed the strategic arms negotiating team.

Conservatives withheld support because Nitze had engaged his Soviet counterpart in an attempt to develop a negotiating approach, later termed "the walk in the woods," without first obtaining approval from Washington. He was admonished by the national security affairs adviser at the time, William P. Clark.

"The president really hasn't faced up to the question yet," said one official about the special envoy choice. "He'll start doing that in Washington next week."

The Geneva meeting also could pursue the possibility of some immediate, good-faith gestures such as the exchange of monitors for underground nuclear tests, which Reagan offered in his September speech to the U.N. General Assembly, the sources said.

They added that next week's meetings here, in addition to deciding whether to pick a special envoy, will seek to resolve disputes within the administration about whether Shultz should go to Geneva prepared to offer some good-faith gesture as an incentive to the Soviets or whether he should adopt a more reserved posture of merely listening to what Gromyko has to say.

According to the sources, administration moderates led by Shultz and Robert C. McFarlane, Reagan's national security affairs adviser, are expected to suggest in the interagency talks that, once actual negotiations with the Soviets begin, the United States be prepared to offer such steps as a moratorium on testing of antisatellite and space weapons or a temporary halt to the deployment of U.S. intermediate-range missiles in Western Europe.

But, the sources added, the harder-line faction centered in the Pentagon believes such concessions should be held back until the United States has a clearer idea of what reciprocal gestures the Soviets might offer and whether the Geneva meeting will lead to a new start on the talks that have been in limbo since late last year.

For their part, Pentagon officials said yesterday, a reasonable good-faith effort by the United States would be to invite Soviet scientists to monitor a U.S. underground nuclear test to show how unobtrusive such an on-site inspection could be. That approach, Pentagon sources said, would not have as harmful an effect on U.S. weapons programs as would a moratorium on space weapons or a delay in deploying the intermediate-range cruise and Pershing II missiles in Western Europe.

Deputy White House press secretary Marlin Fitzwater said yesterday in Santa Barbara, Calif., where Reagan is vacationing, that the United States does not intend to slow the deployment schedule in advance of new negotiations with the Soviets. Asked about the possibility of such a gesture, Fitzwater said: "There are no preconditions and no change in the deployment schedule."

He hinted, however, that the administration might be considering holding such a move in reserve, saying: "We do, however, think that mutual restraint is an appropriate item for discussion in the talks."

McFarlane, in announcing the Geneva meeting at a Thanksgiving Day White House news conference, described the special envoy as a trouble-shooter or "designated hitter to ensure that momentum [in arms control talks] is sustained over time." He stressed, though, that such a person would not be "an arms control czar" who directs policy from Washington.

Scowcroft, who was national security affairs adviser under President Gerald R. Ford, was informally sounded out in recent weeks. However, he is understood to have argued that the job should include policy direction of the overall arms-control program -- something that Shultz, Weinberger and McFarlane all oppose.

McFarlane said yesterday on the "CBS Morning News" that the administration had been reviewing its positions and the Soviet approaches to strategic and intermediate-range nuclear weapons as well as space systems. The aim, McFarlane said, has been to "see if there are common features which may comprise a new direction the other side might find appealing."

U.S. and Soviet positions during the past three years of negotiations on nuclear arms have been controlled by the NATO plan to deploy 572 new, single-warhead, American Pershing II and cruise missiles in Western Europe to balance Soviet SS20 missiles, each of which carries three warheads.

To date, roughly 100 new U.S. missiles have been deployed; Pentagon sources said recently that the SS20 total is above 378.

During the three years of negotiation, both sides had agreed to modify their positions though the Soviets never agreed to a number that permitted deployment of any American missiles before they broke off the talks last November.

The strategic weapons discussions were dominated by the initial U.S. proposal for deep reductions in both land-based ICBM launchers and warheads -- cuts that would have had a much greater effect on the Soviet missile force, where two-thirds of its strategic warheads were on the big missiles the U.S. proposal wanted to reduce. Later U.S. modifications kept the original limit of 5,000 warheads for each superpower, but permitted more flexibility for each side to choose how many land- or sea-based missiles it would need.

Before they walked out on these talks on Dec. 8, 1983, the Soviets had modified their initial position, reducing the overall launcher limit to 1,800 and agreeing to the idea of warhead limits without stating a number.

On nuclear weapons overall, the Soviets have been pressing for a freeze on production and new deployments, a step the Reagan administration has steadfastly refused to consider.