A team of U.S. officials left for the Soviet Union last night to inspect three radars that President Reagan has alleged are in violation of the 1972 Antiballistic Missile (ABM) Treaty.

The team, responding to a Soviet invitation, plans to inspect and photograph the radars, located at Moscow and Gomel, over a four-day period and return to the United States by Dec. 23, according to State Department officials.

The officials said the Soviets rejected a U.S. request for inspection of facilities nearby believed associated with the radars, but that the U.S. team hoped to get Soviet permission for an inspection after they arrived.

Reagan said on Dec. 2 that the 15-year-old radars, known to Western analysts as Pawn Shop and Flat Twin, violated the ABM Treaty because they were moved after being tested with rudimentary ground-based missile defenses at an agreed ABM test range at Sary Shagan, in south-central Russia.

In a report to Congress, Reagan said although "it is not likely that the actions at Gomel are to support an ABM defense at that locality," the redeployment was still "inconsistent" with Soviet treaty obligations. Other U.S. officials have called the radar redeployments a "technical" treaty violation of little military significance.

The Soviets have acknowledged moving the radars, but said they were never used as ABM radars and had been placed under civilian control. They said the Flat Twin radar had not been reassembled, which U.S. intelligence officials confirm. They also provided photographs showing removal of electronic equipment for the two Pawn Shop radars.

Col. Gen. Nikolai Chervov, chief of the arms control directorate of the Soviet General Staff, said during a visit to Washington two weeks ago that U.S. inspectors would "see for themselves that whatever concerns {they have} are just one soap bubble."

Two correspondents for the official Soviet news agency Tass wrote on Dec. 6 that when they visited the Pawn Shop radar near Moscow, they found "nothing but bare walls and empty compartments." They quoted a local official's explanation that the van was being readied to test new radars for civil aviation.

The U.S. inspection team is headed by Manfred Eimer, a longtime assistant director of the Arms Control and Disarmament Agency's Bureau of Verification and Intelligence, who is making his first trip to the Soviet Union. Five radar experts from the Pentagon and the State Department will join Eimer and an interpreter and political officer from the U.S. Embassy in Moscow.