The Washington Redskins, unable to come to an agreement with disgruntled free safety Mark Murphy, have decided to trade him, Coach Joe Gibbs said yesterday.

"Mark has asked to play elsewhere and we've given his agent the freedom to talk to anybody else," Gibbs said at Redskin Park, exactly one week before the opening of training camp in Carlisle, Pa.

"From the very beginning, I've been trying to convince him that this (Washington) was the best place for him, the best opportunity, but I think he feels led the other way," Gibbs said.

Although Murphy and his agent, Donald Dell, were unavailable for comment, it was learned that the Buffalo Bills have expressed interest in Murphy, an eight-year NFL veteran who grew up in suburban Buffalo and graduated from Colgate University in Hamilton, N.Y.

Bills General Manager Terry Bledsoe said he and Redskins General Manager Bobby Beathard talked about Murphy recently, but would not give details.

Beathard, who said he had no success in trying to deal Murphy to the Bills, said he did not know if Dell and Bledsoe had spoken, but added that as far as he knew, no deal had been made with the Bills or with any other team.

Dell, whose ProServ clients include a number of tennis players, has been at Wimbledon and is expected back in town by the end of the week.

Murphy, a Pro Bowl starter in 1983 who missed nine games last season with a knee injury and never regained his starting spot, skipped the team's May minicamp when the Redskins would not give him the guarantees of playing time and money that he wanted.

He accused the Redskins of not playing him last season because of his union activities during the 1982 strike season. Murphy was the Redskins' player representative and a member of the executive committee of the National Football League Players Association in 1982. He now is vice president of the NFLPA.

The Redskins repeatedly have denied Murphy's charges.

Murphy, who will turn 30 Saturday, has been accepted at Georgetown University Law School and has said privately that he might retire from football.

"Mark's meant a lot to the team here and has been a heck of a guy," Gibbs said. "We want to get things (a trade) worked out for him."

The Redskins have other pressing concerns. No. 1 on the list is cornerback Tory Nixon, their second-round draft choice who remains unsigned. Beathard met twice with Larry Muno, Nixon's agent, last week in California, but they did not come to an agreement.

Beathard said Muno gave him "every indication" Nixon will sign by next Thursday and report to camp on time.

Beathard also said he expects veteran defensive tackle Dave Butz, a free agent, to sign soon and to be in camp when the veterans report July 27, although Butz said by telephone this week that he and the Redskins "haven't met halfway."

Butz, unlike most Redskins, negotiates his contract with owner Jack Kent Cooke, not Beathard.

The other unsigned free agents are defensive tackle Tom Beasley, kicker Mark Moseley and running back John Riggins.

Beathard said he doesn't expect Beasley to be in camp because of problems with contract negotiations, but said the Redskins and Moseley "are not that far apart."

Riggins also negotiates with Cooke.

Nine of the Redskins' 12 draft choices remain unsigned, prompting Gibbs to say, "It concerns me . . . I'm hoping things move along in a hurry because it's going to impede our progress as a team."

In another matter, Gibbs said he and wide receiver Charlie Brown have patched up differences. Brown said this week he is working out every day and is happy to still be with the Redskins.

Brown, Art Monk and Calvin Muhammad will be given equal practice time with the first team, Gibbs said. Brown, a two-time all-pro, threatened to leave if he was not given a shot at regaining his spot in the starting lineup.