U.S. intelligence officials, proposing a major step back from administration arms control policy, have told the White House that certain intelligence installations must be exempted from the on-site inspection provisions of future treaties limiting medium-range missiles and strategic weapons being negotiated in Geneva, senior U.S. officials said yesterday.

President Reagan has not made a decision on the proposal, which has been vigorously disputed within the administration, but he may do so before leaving today for the Venice economic summit, the officials said.

Several officials privy to the dispute said acceptance of the intelligence community's proposed exceptions would be a significant retreat from the administration's longstanding insistence that compliance with arms control agreements cannot be verified unless the United States and the Soviet Union can inspect the sites of suspected violations in each other's country on short notice, without exemption.

Largely at the behest of the Defense Department, which opposes granting any exemptions for such on-site inspection, the requirement was explicitly included in a 1984 U.S. draft treaty banning chemical weapons, and U.S. officials planned to include it in draft U.S. treaties on strategic weapons and medium-range missiles in Europe introduced in Geneva earlier this year.

But officials of the Central Intelligence Agency, the National Security Agency and the Federal Bureau of Investigation have told the White House that the risks from allowing Soviet inspectors to roam through their intelligence-gathering facilities under such a provision outweigh the benefits of potential access to secret military sites in the Soviet Union, U.S. officials said.

The dispute arises as Soviet officials have apparently overcome their longstanding opposition to on-site inspections. In the proposed pact on chemical weapons, the Soviets have explicitly endorsed the concept of inspections of suspect facilities on short notice, and American negotiators have been hopeful that they will accept it as well in new missile pacts.

The Soviets have continued to insist on more limits on on-site inspections than the Reagan administration has favored, however, causing U.S. intelligence officials to argue that the Soviets would probably welcome exemptions, too, since Moscow is at least as sensitive as Washington about its intelligence facilities.

Proponents of the exemptions say they would thus eliminate what some Western officials fear could become a stumbling block to agreement on medium-range missiles in Europe.

The intelligence community fears that the Soviets might learn too much about U.S. intelligence-gathering technology by inspecting sensitive sites under the guise of checking on potential U.S. treaty violations, the officials said. Opponents of the exemptions argue that once the principle of exemptions is accepted on both sides, the Soviets might be able to hide treaty violations by claiming that the sites of such violations were sensitive intelligence-gathering facilities.

State Department officials said yesterday that Secretary of State George P. Shultz and Soviet Foreign Minister Eduard Shevardnadze may meet this summer to try to push forward an agreement on medium-range missiles.

U.S. and Soviet negotiators in Geneva said yesterday that they had successfully put rival provisions of their draft treaties into a single document, an important procedural step in the ongoing negotiations, but that some important differences remain.

At a contentious White House meeting last Thursday of the Senior Arms Control Group, chaired by national security adviser Frank C. Carlucci, the intelligence community proposal was also supported by the State Department and the Energy Department.

Lukewarm support for exemptions to on-site inspection has also been expressed by officials of the Joint Chiefs of Staff and the Defense Intelligence Agency in internal administration discussions, the officials said.

But other officials cautioned that the proposal might still be derailed by opposition from Secretary of Defense Caspar W. Weinberger, Arms Control and Disarmament Agency Director Kenneth L. Adelman, and senior arms control adviser Edward L. Rowny, some of whom argued at the Thursday meeting that additional study was needed before abandoning the previous administration policy favoring broad on-site inspections to verify future treaties.

In particular, the intelligence agencies feared that the Soviets might request access on short notice to sensitive facilities where the United States is developing countermeasures to Soviet weapons and intelligence gathering, a knowledgeable official said. "For example, we wouldn't want them to find out about military equipment of theirs in our possession," the official said.

The intelligence agencies have proposed that treaty language be drafted broadly enough to exempt hundreds of sites where foreign intelligence is collected and analyzed, including agency headquarters in the United States and remote listening posts in Europe, the officials said. Other agencies have proposed that the language be drafted broadly enough to exclude only a few dozen of the most vital U.S. installations.

In principle, both sides have agreed to "routine" inspections of installations that both acknowledge have been used to build or store missiles, and similarly obvious targets of interest. Proponents of negotiating new exemptions for intelligence facilities argue that these are the most important on-site inspections, and could continue.

Defense Department officials have argued that once a category of exempted facilities is created, the Soviets will contend that every site of a suspected violation that the United States demands to inspect fits in the exempted category. Even though the installations at some sites might obviously be unrelated to intelligence gathering, the burden would be on the United States to disprove the Soviet claim, and the request would be blocked by prolonged wrangling, the Pentagon said.

"It would basically gut the concept of on-site inspections, because the Soviets would have an excuse to bar us from going anywhere they don't want us to go," an official who is critical of the proposal said.

Proponents of the exemptions claimed that this concern is exaggerated because the definition of exempted sites would be specific and clearly agreed upon in advance, thus limiting the possibility of protracted dispute on inspection requests.

Some intelligence officials also maintain that such inspections are not needed or contribute little to verification of Soviet compliance in comparison to intelligence gathering by remote photographic and electronic sensors.

"There are some tradeoffs," a senior administration official said. "In the end, we probably aren't going to have absolutely perfect verification."