The U.S. Football League offered National Football League Commissioner Pete Rozelle a job as commissioner of the new league in 1982, it was revealed today during cross-examination in the USFL's $1.32 billion antitrust suit against the NFL.

The USFL also apparently asked the NFL if it could pattern its rules after the NFL's rules, sources said today.

Frank Rothman, the NFL's attorney, was planning to introduce into evidence a letter from NFL general counsel Jay Moyer answering a USFL request by giving the new league permission to go ahead and use the NFL's rules, according to several sources familiar with the letter.

"[The NFL] just asked [the USFL] not to Xerox the rules," said one of the sources.

The letter was not permitted to be introduced into evidence today because of procedural matters, but it likely will be introduced later.

During testimony just before court adjourned for the day, Rothman asked Rozelle if the fledgling USFL came to the NFL for assistance. "Yes," Rozelle answered.

When asked if the NFL gave the USFL help, Rozelle again said, "Yes." It was then that Rothman wanted to introduce the letter into evidence.

United Press International reported that Rozelle declined the offer to become commissioner of the USFL because "I was committed to the National Football League."

The USFL's interest in NFL personnel and procedure was one of many issues Rothman touched upon as the NFL turned to the offensive for the first time in the second week of the trial in federal court.

Also today, examination of Monday's court record revealed that Judge Peter K. Leisure said he "will have to seriously consider a motion for a mistrial" if USFL attorney Harvey Myerson asks "inflammatory" questions concerning potential witnesses who have not yet testified.

Leisure sustained an NFL objection to one of Myerson's questions of Rozelle dealing with the promise of a new NFL team for New York City allegedly made to Gov. Mario Cuomo or Sen. Alfonse D'Amato.

Rozelle denied that he wanted to "tie up" all three major networks, as the USFL suit alleges, when he negotiated a contract with ABC for "Monday Night Football" in 1970. CBS and NBC already were televising NFL games.

"My aim was to promote awareness in and increase the prestige of the league," Rozelle said.

Through questioning, Rothman also brought out the number of opportunities there are for college and professional sports to be televised today on the networks, on cable and via syndication.

The topic of the Harvard Business School seminar in February 1984 attended by 65 NFL officials on "How to Conquer the USFL" also came up. Rothman introduced into evidence a March 13, 1984, letter from Moyer to Jack Donlan, executive director of the NFL Management Council, saying the NFL saw "no value" in further consideration of a presentation by Prof. Michael Porter to NFL club executives.

". . . Much of the content of the presentation appears to us to be obvious and the remainder offers approaches that are largely impractical or legally impermissible," Moyer's letter says in part.

Rothman also had Rozelle read from a report on which Porter's seminar was based, quoting then-New Orleans Breakers Coach Dick Coury as saying, "We should have a separate league for Donald Trump, Philadelphia, Michigan and Arizona. Make them a branch of the NFL. That's what they want anyway. We're on a course of self-destruct. We can't make it big by having three or four teams in our league spend a lot of money and go crazy. Where are we going when the whole league doesn't make it?"

When the NFL decided it wanted to begin prime-time telecasts on Monday night, Rozelle said he first went to CBS because of the long-time commitment the network had with the NFL. But CBS told him it did not want to disrupt its Monday night lineup, and NBC showed little interest for similar reasons, Rozelle said.