The U.S. decision yesterday to test an antisatellite weapon against a target in space may prompt the Soviet Union to resume similar testing of its own, Soviet media hinted today.

Official commentaries on the U.S. antisatellite, or ASAT, launch suggested that the Soviet Union may drop the unilateral moratorium against antisatellite weapon testing in effect since August 1983.

"Evidently it would be appropriate to remind the U.S. administration that the unilateral Soviet moratorium on first launching of antisatellite weapons is in effect for as long as other countries, including the United States, refrain from placing antisatellite weapons of any type in outer space," said a commentary by the Soviet news agency Tass.

The same theme was sounded tonight in a report on the main Soviet evening news program.

The threat to resume competition in antisatellite weapons comes in answer to what Moscow sees as negative U.S. responses to recent Soviet arms control initiatives, most of which have been dismissed as propaganda by Washington.

The ASAT test resurrected an issue long overshadowed by the Soviet campaign against the U.S. Strategic Defense Initiative, or "Star Wars" program.

The Soviet tests of an antisatellite system between 1968 and 1982 often has been cited as justification for the long-planned U.S. test. Soviet commentaries never mention that Moscow has tested its own low-altitude ASAT system.

The Reagan administration's decision to proceed with the ASAT test was seen here as a decisive step toward implementing the Star Wars program -- the Soviets' chief concern and main propaganda target for more than a year.

"The Washington-conceived system of antimissile defense with space-based elements and antisatellite systems is called upon to become a material basis for the concept of 'Star Wars,' which . . . is a component element of the U.S. first-nuclear-strike strategy," Tass said.

Tass linked the U.S. ASAT launch to a Soviet proposal last week for an international conference on space and noted that the United States recently conducted an underground nuclear test a week after the Soviet Union announced a unilateral moratorium on nuclear explosions starting Aug. 6 -- the 40th anniversary of the dropping of a nuclear bomb on Hiroshima.

Foreign Minister Eduard Shevardnadze proposed the international conference on halting the militarzation of space in a letter last week to U.N. Secretary General Javier Perez de Cuellar.

The Shevardnadze proposal also urged the creation of a world space organization to coordinate peaceful uses of space and to verify agreements preventing an arms race in space. The proposal is to be considered at the General Assembly session this fall.

The test moratorium was rejected by the United States and the proposed conference has received a cool response -- which Tass called "a clear challenge to the world community, an intentional demonstration of the complete reluctance of the U.S. leadership to embark on the road of curbing the arms race."

Tass commentator Vladimir Chernyshev rejected the White House contention that ASAT testing would provide an "incentive" to the Soviet Union to negotiate limits on such weapons at Geneva. "Someone in Washington believes that the rest of the world consists of simpletons who can swallow and digest any propaganda dish cooked on Washington's recipes," he said.