A Texas manufacturer of a laser device designed to aid referees in professional football games in spotting the ball is suing the National Football League under antitrust laws after the NFL rejected use of the product.

Although the suit has not made sports page headlines, as has the antitrust suit brought against the league by the Oakland Raiders' Al Davis, it points up the primary reason the NFL is looking to Capitol Hill for relief. League officials believe that complex antitrust issues are dominating their business.

"I believe that the league thinks it has been sued more frequently than it should have been and that it has been treated badly by the courts because courts don't seem to understand the league's operations," said John Weistart, a Duke University law professor who has written a widely used textbook entitled, "The Law of Sports."

Weistart, who testified before the House antitrust subcommittee last year on the issue, said in an interview that he would support a "narrowly drawn" antitrust exemption for the NFL, as long it would not affect labor and franchising issues.

Calling a massive congressional effort for the measure the league's top priority, NFL Commissioner Pete Rozelle has announced that the NFL is aggressively seeking antitrust legislation that could moot the heralded Davis case. Davis is charging that the NFL violated the antitrust laws in preventing him from shifting his team to Los Angeles.

The bill also would give the league immunity from a variety of continuing and potential antitrust problems. League attorneys said, however, that their bill would not affect the NFL's complex labor situation. Congressional sources maintain that the NFL's drafts of the bill muddy the labor questions. The NFL Players Association has said that it is adamantly opposed to the antitrust legislation in virtually any form.

Although no member of either the House or Senate has announced a willingness to introduce the measure, which now runs to six double-spaced pages, NFL lobbyists seem convinced a sponsor will step forward within a week. Congressional sources say, however, they know of no support for the bill within either the top leadership of either congressional chamber or within the leadership of the House antitrust subcommittee, which has held extensive hearings on the issue.

The exemption, or clarification, as NFL representatives prefer to put it, would end uncertainty among league management, team owners, competitors and even federal judges about the status of the league in the nation's competitive economic system. The NFL's legal fees, one source said, are more than the operating budget of the league's offices.

The league argues that professional football, and all of professional team sports, are unlike most other businesses. Simply put, that status stems from the fact that NFL teams, although separately owned, behave in ways that run counter to the competitive traditions of the Sherman Act, the nation's primary antitrust statute.

Owners of NFL teams, who in effect operate independent businesses, meet to discuss a variety of issues concerning the league, meetings that in almost any other field would give an industry's antitrust lawyers heart failure.

"A board of directors can have a meeting without worrying about the Sherman Act," argues Paul Tagliabue, a Washington attorney for the NFL. "Our bill deals solely with the limited aspects of selling entertainment in competition with other forms of entertainment."

The bill, Tagliabue said, would apply only to limited "league prerogatives," such as the NFL's revenue-sharing policies. "The league would operate like a law firm in which the partners meet to share revenues," he said. The bill would recognize, he added, that there must be a legal "rule of reason" that would be used to monitor league behavior in particular situations.

On the other hand, Ira Millstein, a New York antitrust lawyer who has represented the North American Soccer League Players Association and the National Basketball Association Players Association, calls the NFL's arguments for the legislation "absolute nonsense." An appeals court recently upheld an NASL victory against the NFL. That suit charged the NFL with an antitrust conspiracy against the soccer league.

"By what right does the NFL have to get itself exempted from the antitrust laws?" Millstein said. "I'm not saying anything they do is a restraint of trade. There is no question they can keep gamblers from owning teams, for instance, or jointly market T-shirts.

"But things not related to putting on a game would be unreasonable," Millstein added. "There is nothing unique about their operations. There are dozens of decisions which spell out exactly what the league can and can't do."