President Reagan should pursue the offer of Soviet President Yuri V. Andropov to ban anti-satellite weapons from space by "immediately" offering to negotiate a moratorium on further testing, a leader of the Union of Concerned Scientists said yesterday.

Kurt Gottfried, a physics professor at Cornell University who chaired the scientists' panel on anti-satellite weapons, said in a telephone interview that a mutual U.S.-Soviet ban on anti-satellite weapons not only would keep the arms race from moving into space but would be in "our narrow military interest" as well.

"We should offer a bilateral test ban immediately," Gottfried said.

"It would be foolish and short-sighted," he contended, to ignore Andropov's offer in hopes of exploiting the current U.S. lead in anti-satellite technology. The Soviets would catch up, he said, and develop weapons that could knock down the reconnaissance, navigation and communication satellites on which U.S. forces are more dependent than are their Soviet counterparts.

President Carter, Gottfried continued, pursued a two-track policy in anti-satellite technology, developing the weaponry while pursuing an agreement to ban their use. The negotiation track should be reactivated, Gottfried said.

Andropov, in a meeting with two U.S. senators in Moscow Thursday, said he was "prepared to dismantle the existing anti-satellite weapons systems" as part of an agreement banning "future development of such weapons."

The Soviet news agency Tass said the Soviets would not be the first nation to deploy anti-satellite weapons and would agree to a ban on launching them if the United States and other nations did likewise.

The Soviets have been experimenting with anti-satellite weapons, which primarily consist of a satellite that intercepts a target satellite and then explodes near it, destroying it with shrapnel.

Pentagon space specialists consider these Soviet weapons a limited threat to low-flying reconnaissance satellites, not the high-flying communications satellites that hang over the same spot on Earth at an altitude of 22,335 miles.

The United States is close to flight-testing a more versatile satellite killer, nicknamed the "flying tomato can," which an F15 fighter could carry to the edge of space and then launch. The weapon would home on the target satellite's heat and destroy it.

Pentagon ideas for killing satellites include firing pellets and hitting them with a flying "umbrella," an orbital weapon that extends metal arms before colliding with the target. While pursuing such offensive anti-satellite weapons, Pentagon specialists are working on ways to protect U.S. satellites, such as "parking" them higher in space than the Soviets could reach.

The Union of Concerned Scientists recently issued a 44-page report on anti-satellite weapons. It warned that if the United States does not respond to the Soviets' draft treaty of August, 1981, to ban "the stationing of weapons of any kind in outer space," it "will have adopted a new strategy of ongoing confrontation for protecting its space assets."

A U.S.-Soviet moratorium on further anti-satellite tests in space would not jeopardize U.S. security even if a treaty permanently banning such activity could not be negotiated or was broken or circumvented after it was agreed upon, the report argued.