U.S. Football League owners and the league's players association have reached tentative agreement on the concept of a salary cap as part of a collective bargaining agreement.

In addition, tentative agreements in other areas of the collective bargaining agreement will enable the two-year-old league to go directly from a spring season in 1985 to a fall season in 1986, Commissioner Chet Simmons said today at a briefing on the 1985 season.

From Washington, Doug Allen, executive director of the USFL Players Association, said that his group considers nothing as agreed upon until the entire contract is settled.

Among the areas of continued negotiation, according to Allen and Paul Martha, chief negotiator for the owners, are benefits, free agency, allocation of players whose teams were consolidated into the current 14-team setup and length of contract.

But Allen said the players association has agreed to the concept of a salary cap, with negotiations continuing on specifics. Allen said that the degree of free agency allowed USFL players will have a bearing on the issue of a salary cap. Martha said he expects the collective bargaining agreement to be completed within two weeks.

Sources indicated that the salary cap would enable players to keep about 55 percent of gross revenues. A few players would be exempted from the salary cap on each team.

USFL owners attending today's press briefing at the Essex House said a salary stabilization plan was imperative, as Houston owner Jerry Argovitz put it, to put the league in a position to compete against the NFL in the fall.

While neither Allen nor the owners were willing to discuss specifics of negotiations, Allen made it clear that the USFLPA was satisfied if players were paid their regular salary on a February-to-December basis in 1986. Otherwise, they would receive no paychecks from the end of the 1985 season in July for more than a year, when the season resumes in September 1986.

On a day when Simmons presented the league in its most positive image, there were these other developments:

*Realignment: There will be a 14-team league. Oklahoma has merged with Arizona and Michigan with Oakland. The Baltimore Stars have assumed contract obligations of the Pittsburgh Maulers, whose owner, Edward J. DeBartolo Sr., has become a 50 percent owner of the Stars. The Chicago franchise, owned by Eddie Einhorn, will not play next season, but will resume as an expansion team in 1986.

There will be two seven-team conferences next season. Baltimore, Birmingham, Jacksonville, Memphis, New Jersey, Orlando and Tampa Bay will comprise the Eastern Conference. Arizona, Denver, Houston, Los Angeles, Oakland, Portland and San Antonio will be in the Western Conference.

*Playoffs and scheduling: Eight teams will participate in the 1985 playoffs, including the top two finishers in each conference and the next four teams with the best records. Each team will play conference opponents twice, with six interconference games. The 1985 championship game probably will be played at the Meadowlands, Simmons said.

*Litigation: The league's $1.2 billion antritrust suit against the NFL continues "full steam ahead," according to Roy Cohn, the league's lead lawyer in the case. Cohn said he wrote NFL attorneys last week, charging that the NFL and some of its teams are conspiring in violation of the antitrust laws by "dangling a carrot" of an existing NFL team or an expansion team to discourage communities from dealing with the USFL.

Cohn said four cities were involved, but he declined to name the teams or give specific examples. Owners Fred Bullard of the Jacksonville Bulls and Ted Dietrich of the Arizona Wranglers said officials in their cities had been approached.

There have been published reports that the owners of the New Orleans Saints have talked to Jacksonville officials, and Phoenix officials have had discussions with Leonard Tose, owner of the Philadelphia Eagles, and Bill Bidwill, owner of the St. Louis Cardinals.

Joe Browne, an NFL spokesman, said it is "utter nonsense as far as any conspiracy" that the NFL or NFL team owners had colluded in trying to discourage communities from dealing with the USFL.

Cohn also said NFL Commissioner Pete Rozelle had been subpoenaed to give a deposition in the antitrust suit on Dec. 13.

*Television: Though two networks say they are not interested in televising the USFL in fall 1986, but are interested in subsequent years, Simmons said discussions are continuing with all three networks.

"It would appear that we are the bride with the wedding gown and no groom. Perhaps, but if anyone in this room believes that a network executive would share confidential information regarding network negotiations with the news media, I have a beautiful bridge in Brooklyn, and the price is right.

"I can offer a few observations that may put the situation in perspective," Simmons said. "For one thing, the networks need us. They need us because we offer an exciting, salable product at nowhere near the cost of the NFL, and the possibility of substantial profit margins. We do not come cheap, but we certainly do not require the $500 million that the NFL demands today."

League sources said the USFL would need $100 million to $120 million in television revenue to break even in 1986.

The league already has a three-year, $70 million cable deal with ESPN, starting next spring. Einhorn said games will be televised on cable three nights a week in the spring (Friday, Saturday and Monday), and three nights a week in the fall (most likely Thursday, Friday and Sunday).

"We started as a spring league and could have stayed that way," Simmons said. "The fact is that with our player signings and the virtually geometric increase in the quality of play, we simply outgrew the original plan. We raised the stakes and found that the financial support we needed was not there in the spring and summer. I can guarantee that we, too, will hold on and be successful."