Charles Sullivan, vice president of the New England Patriots, said today the club will take legal action if necessary in an effort to retain Chuck Fairbanks as coach of the team.

"He may get to Colorado," said Sullivan, "but not without a fight."

He was asked if that meant the Patriots would take legal action if Fairbanks tries to follow through on his announced intention to coach at the University of Colorado.

"Yes, we will," said Sullivan.

Sullivan discussed the Fairbanks situation at halftime of today's AFC playoff game, won by the Houston Oilers, 31-14. It was 21-0 at the half.

"This is the worst first half the team played this season," said Sullivan, "and it is obvious that Fairbanks had his mind on the job at the University of Colorado."

Sullivan was asked if he thought the precedent of Warren Powers having to reimburse Washington State University for the remaining years on his contract was pertinent. Powers left Washington State for the University of Missouri.

"I regard it as very significant," said Sullivan, who is an attorney and son of Patriot President William H. Sullivan Jr. "But we are not interested in money. We want Fairbanks as coach."

Sullivan said that Fairbanks did not try to renegotiate a new contract from the Patriots by using the Clorado offer as a bargaining ploy.

Fairbanks announced at a team meeting a few hours before the Patriots' last game of the regular season, in Miami, that he was resigning to accept the coaching job at Colorado.

The Patriots contended that the 45 players were their witnesses that Fairbanks had breached his contract, which has four years remaining.

Under threat of legal action, the Patriots persuaded Fairbanks to rejoin the team for the playoffs. The coach was prevailed, upon to send a telegram to Colorado saying be could not negotiate with the university or execute a contract with the Buffaloes until after the playoffs.

Meanwhile, there was speculation here today that John Madden of the Oakland Raiders might become the new coach of the Patriots or the New York Giants.

Al Davis, managing general partner of the Raiders, came east about a week ago and was said to be considering letting Madden go in exchange for draft choices. A precedent for such a swap was set when Don Shula left the Baltimore Colts to go to Miami.

When former owner Carroll Rosenbloom of the Colts charged the Dolphins with tampering, Commissioner Pete Rozelle awarded the Colts a No. 1 draft choice from the Dolphins as compensation.

There also is speculation that the San Francisco 49ers are considering a big shakeup. John Thompson, general manager of the Seattle Seahawks, a few days ago was offered the same position with the 49ers, but turned it down.

That has been interpreted as meaning Joe Thomas will be leaving the 49ers as general manager. It is believed that he would get a settlement from owner Ed DeBartolo as a compensation for helping DeBartolo buy the franchise.

Madden is said to want to stay in California, suggesting the 49ers would have the inside track over the Patriots and Giants. Rosenbloom, owner of the Los Angeles Rams, also is believed to rate Madden's coaching talents highly.

A source here said the Giants are seriously interested in hiring as general manager or personnel director Jack Butler, former personnel chief for the Pittsburgh Steelers and now head of the BLESTO scouting pool.