In a decision union officials say could have major significance, an administrative law judge yesterday found the National Football League guilty of unfair labor practices for refusing to disclose to the NFL Players Association the non-monetary particulars of its television and radio contracts.

Ed Garvey, executive director of the striking NFLPA, called the decision "a nice clear signal to all the owners in the league that this is a serious step toward establishing this strike as an unfair labor practice strike." Such a ruling would make players eligible for back pay for games missed during the strike, he said.

Said Jack Donlan, the NFL's chief labor negotiator, "That's nonsense. This is a recommendation to the National Labor Relations Board and then the board has to go to court. There isn't anything in there that would create a condition that the players struck over. There is a big, big difference between a decision by an administrative law judge and an unfair labor practice strike."

Donlan said he will appeal the decision, which goes now to the full, five-member NLRB. After that, the issue goes to the federal courts. The entire process could take a year.

Donlan also said he has rejected Garvey's proposal that negotiating subcommittees for the two sides meet today and Thursday morning to discuss such issues as grievance procedures, pensions and insurance and a joint counseling program. Full scale contract talks are to resume Thursday afternoon.

"Your refusal to meet until Thursday afternoon eliminates any opportunity to play this coming weekend," Donlan said in a message to Garvey. Sunday, NFL Commissioner Pete Rozelle said next weekend's games would have to be called off if the strike was not settled by Thursday. The league has not officially called off the games.

The decision on the unfair labor practice charge came just two days before Garvey and Gene Upshaw, union president, of the Los Angeles Raiders are to testify on Capitol Hill. The NFLPA contends the agreement between the NFL and the networks violates antitrust laws by requiring payments of television rights for the first two games not played because of a strike.

Garvey and Upshaw are to appear as witnesses Thursday before the House Judiciary Committee. The committee is considering an NFL-backed bill that would protect from antitrust lawsuits its current practice of revenue sharing and rules on franchise relocation. The relocation measure would be retroactive, permitting the NFL to force the Raiders to return to Oakland.

Yesterday's administrative law decision was handed down by Judge Julius Cohn after three days of testimony on an NLRB complaint filed against the NFL and the NFL Management Council, the league's labor negotiating arm, last June in New York. Cohn directed the league to supply the union with copies and memoranda of all nonmonetary items of its television and radio contracts as well as all player contracts. Garvey says the union needs that information to bargain effectively.

Spokesmen for all three networks have confirmed that their contracts with the NFL call for payments for the first two games not played because of a strike. Neal Pilson, president of CBS Sports, said yesterday any payments the network makes ultimately will be reduced by two weeks if the games are not made up.

Jim Spence, senior vice president for ABC Sports, said the NFL will either have to refund the money for a Monday night game not played or the network would get additional commercial time in a future game.

But, Spence said, "They are so far apart that even if the clause that they find so odious were not there, I don't think the strike would be any shorter."

In a strike-related development yesterday, the union announced a schedule and locations for 20 all-star games by striking players, beginning with a game Oct. 10 at 4 p.m. at RFK Stadium in Washington between the National Football Conference East and the American Football Conference East.

The management council has said it considers such games to be a violation of the players' standard NFL contract, which prohibits them from playing in any game not sanctioned by the league. Donlan said yesterday the council will go to court to enforce that provision. The union has filed a lawsuit in U.S. District Court here seeking a ruling that players are free to participate in such games.

Former Washington Redskins linebacker Chris Hanburger will coach the NFC East team. All the teams will be chosen by ballot of NFL players.

The other coaches are Tom Matte, former running back for the Baltimore Colts, AFC East; Willie Wood, former free safety for the Green Bay Packers, NFC Central; Mike Pyle, former center for the Chicago Bears, AFC Central; Johnny Roland, former St. Louis Cardinals running back, NFC West, and Bobby Layne, former quarterback with the Detroit Lions, AFC West.

The games will be syndicated nationally by the Atlanta-based Turner Broadcasting System, both to its 22 million cable homes and to 73 network affiliates and independent television broadcast stations who bought the package. As of yesterday, no Washington or Baltimore station had purchased rights to the games.

Bob Wussler, president of Turner Broadcasting, said the NFLPA has been guaranteed at least $500,000 a game, but that he hopes the union's share will be $750,000 or $1 million a game. A game will be played each Sunday afternoon and Monday night.

Players on winning teams will be paid at least $3,000 a game and those on losing teams will get at least $2,500, said Brig Owens, a former Washington Redskins player who is a union official and "commissioner" of the players' all-star league. Asked how he felt about the NFLPA's doing business with Turner Broadcasting, a nonunion firm, Owens said, "This is an opportunity to provide some work for our people."

He avoided specific answers to questions about insurance coverage, but said a player would be fully insured if his career is ended by an injury in one of the NFLPA sponsored games.

Robert Sigholtz, general manager of the Stadium-Armory Board, said the lease for RFK Stadium calls for $15,000 or 15 percent of the gate, whichever is greater.