The attorney for Sugar Ray Leonard said yesterday he has been approached by a group from the Soviet Union seeking to host Leonard's next ring appearance.

Mike Trainer, Leonard's longtime attorney and adviser, had narrowed the list of potential venues to France and Italy before receiving interest this week from what he described as a commercial group in the Soviet Union, throwing negotiations "up in the air again."

Eventually, one of those three countries will be chosen for Leonard's first bout outside the United States since 1980, when the five-time world champion suffered his only career defeat, to Roberto Duran in Montreal.

Trainer said he was unable to estimate how long it will take to finalize the details for Leonard's first fight since December, when he scored a unanimous decision over Duran.

"We're still working on it," Trainer said yesterday by telephone from his office in Bethesda. "Obviously, I thought we would have something by now. I have nothing {definite} to report."

Leonard still is the World Boxing Council super middleweight champion although he has tried to relinquish his crown; the WBC will not allow him to do so.

Trainer said Leonard's opponent probably will come from the country the fight is held in. However, if the bout takes place in the U.S.S.R., Leonard will not fight a Soviet. Most of the Soviets who have turned professional are fighting in the United States.

"Once we zero in on a country, we'll probably find someone from that country," Trainer said. "But in the event we fight in {the Soviet Union}, we'd probably have to take someone with us."

Trainer began to pursue an overseas bout for Leonard when he and and handlers for Thomas Hearns couldn't agree on a suitable weight limit. Leonard normally weighs about 160 pounds; Hearns reportedly won't agree to a fight at less than 163. Leonard's other main rival, Marvelous Marvin Hagler, retired after losing to Leonard in April 1987 and now is an actor in Italy.

Leonard and Hearns met as welterweights in 1981, with Leonard stopping Hearns in the 14th round. Last June, at a limit of 164 pounds, they fought to a draw in which Hearns scored two knockdowns.

"If {Hearns} goes on the Slim Fast diet, we'll talk to him in the future," Trainer said. "Ray won't be fighting him in the fall."