Sugar Ray Leonard, World Boxing Council champion, will fight Jose (Pipino) Cuevas, World Boxing Association titleholder, for the undisputed welterweight championship of the world on Friday, May 16, Promoter Bob Arum said yesterday.

Arum said the site has not been decided, but it probably will be either in Las Vegas or in the northeast.

It will be part of a three-hour boxing show on ABC-TV which will include a middleweight championship bout from another site.

Plans to have Eddie Gregory defend his new WBA light heavyweight title the same night had to be canceled because Gregory suffered a cut eye Monday night taking the title from Marvin Johnson.

Cuevas, from Mexico, will defend his title in a tuneup for Leonard against Harold Volbrecht, South African champion on Sunday in Houston. That fight will also be televised.

New Orleans promoter Denzil Skinner said he had to turn down the Leonard-Cuevas bout because the Superdome is being use on May 16 for a trade show. Skinner said he is going ahead with plans to promote a bout between Mike Weaver, WBA heavyweight champion, and Muhammad Ali.

"We're sick about not being able to have Leonard-Cuevas," he said "but we hope to have Leonard against Roberto Duran in the fall."

Skinner said that a projected Ali-John Tate bout "lost some of its glamor when Tate lost his title on Monday to Weaver. But Ali was the big news, and still will be against Weaver.

"Larry Holmes (WBC champion) is out as an opponent for Ali because Holmes wants $4 million. We can't pay that with what Ali wants."

Ali was asking $6.5 million to fight Tate, who wanted $2 million. Skinner said, "We expect to have an announcement about an Ali-Weaver bout next week."

A spokesman for CBS said Duran has been booked for "a major bout" on Saturday, May 17. He is the former lightweight champion now ranked No. 1 welterweight contender by the WBC and WBA.