Fullback John Riggins, representatives of the NFL Players Association and lawyers for the Redskins and the National Football League met behind closed doors yesterday with arbitrator Bert Luskin on the first day of binding arbitration on Riggins' contract dispute with the Washington club.

None of the parties would comment in detail on the proceedings, but Luskin said, "We had a very productive day. We're about a third of the way through. We'll meet again Friday and, if we have to, we'll meet Friday night and all day Saturday."

Luskin said there would be no immediate decision at the end of the hearings and that he would need time to review the material.

Riggins contends the Redskins violated his rights by placing him in the "left camp-retired" category following his departure from training camp last summer after the Redskins refused to meet his demand that the option year of his contract be changed to a one-year, $500,000 guaranteed contract.

Riggins contends he changed his mind after leaving camp and wanted to play last year, but that the Redskins' action prevented him from doing so.

Redskin General Manager Bobby Beathard disputed statements Monday by NFLPA Director Ed Garvey that Riggins had notified the club in a telegram that he wanted to play.

"He never expressed a desire to return to our team," Beathard said.