President Reagan has categorically rejected appeals from the Soviet Union and from some of his advisers to negotiate a detailed agreement on what kinds of tests of exotic missile-defense technology are permitted under the 1972 Antiballistic Missile (ABM) treaty, according to a senior Reagan administration official.

Proponents of a negotiated agreement to clarify what some U.S. and Soviet officials consider ambiguous language in the ABM treaty argue that this would be the best means of overcoming a stalemated U.S.-Soviet dispute over the proper interpretation of the 15-year-old treaty.

After it was suggested by Soviet Foreign Minister Eduard Shevardnadze in Moscow in April during a visit by Secretary of State George P. Shultz, a negotiation on missile-defense tests was formally proposed by the Soviets at ongoing talks in Geneva on strategic arms and missile defenses.

The senior U.S. official, speaking on condition that he not be identified, said that Reagan had decided "we do not want to negotiate on that basis" because "the Soviets see this as a way to kill the SDI {Strategic Defense Initiative} program," which is aimed at developing a comprehensive U.S. ballistic missile defense. The remarks were made at a symposium on arms control attended by officials from the White House, the Defense Department, the State Department, intelligence agencies and the Arms Control and Disarmament Agency.

The official added that such an agreement on missile defense tests that are prohibited and permitted by the ABM treaty would necessarily be extremely complex, and "I really don't see how you can get into that never-never land. You're taking enormous risk and for what purpose?"

The official said at one point that "I don't see any reason" why the Pentagon should be prevented from following a controversial "broad" or permissive interpretation of the treaty that was endorsed by Reagan in 1985, but subsequently suspended in response to protests from Congress and U.S. allies.

Reagan has been considering a proposal from Secretary of Defense Caspar W. Weinberger to follow the broad interpretation by conducting realistic tests of exotic missile defense technologies, which the Soviets believe the treaty bars. The idea of negotiating an agreement with Moscow on the details of such tests has been proposed by senior State Department adviser Paul H. Nitze and others as a means of overcoming Soviet objections and ensuring continued congressional support for the tests.

The senior official said the question of whether to adopt the broad interpretation of the ABM treaty "is not a legal issue, it is a national security issue . . . . We do not think at this point that there should be constraints on the development of this {SDI} system." Key members of Congress, including Senate Armed Services Committee Chairman Sam Nunn (D-Ga.), have disagreed sharply, and warned the administration not to adopt the broad interpretation.

The official also played down any chance of U.S. concessions on SDI in exchange for an agreement with the Soviets on strategic nuclear arms, as the Soviets have demanded.

"The basic problem I see with arms control is that it seems to have mesmerized the American people, and we seem to see it as a panacea for all our problems," the official said.