George Allen officially was named president and chief executive officer of the Montreal Alouettes yesterday, but said he will not exercise an option to become part-owner until the beleaguered Canadian Football League team is debt free.

Whether Allen also coaches the team remains to be seen. He said he would make that decision within a month, once he settled the team's front office problems. Since the end of last season, when the Alouettes finished 3-13, most of the ranking team officials have been fired.

Allen, who once told Washington Redskins fans "the future is now," marked his return to pro football after a four-year absence by promising the Alouettes "the future is ours."

He also said he no longer would be the free spending Allen of the National Football League years.

"I'm an owner now," he said at a press conference in Montreal.

Technically, Allen is not an owner. He has an option to buy 20 percent of the Alouettes by Dec. 31 and a second option to buy all or another portion of the franchise by Dec. 31, 1983. He won't exercise any of those options, he said, until owner Nelson Skalbania pays off the team's $1.4 million debt.

Montreal sources said it would cost $600,000 to $700,000 to buy 20 percent. Allen said he still is forming a group of backers, and that wealthy Californian Willard Harris would be one of the investors.

"Nelson has committed to me that he will pay any past debts," Allen said. "Part of the agreement is that there will be a clean slate. We will try to do things as stringently as we can. The most important thing is to establish good credibility and pay all our bills."

Skalbania said "sooner or later" Allen would buy the team. "I hope sooner," said Skalbania, who lost $4 million in his first and so far only year as owner, "because I'm going to blow my brains out."

If Allen does decide to buy at least 51 percent, his bid would have to be approved by the Canadian Foreign Investment Review Agency. No U.S. citizen ever has owned a majority interest in a Canadian team.

Allen last was in football as coach of the Los Angeles Rams, who fired him in August 1978. Since, he has been a television commentator for NFL games and has sought unsuccessfully to find another NFL coaching position. He has claimed that he was being blackballed by league owners, who allegedly were wary of his reputation for exceeding both the budgets and the authority given him.

"The attractiveness of this situation was Montreal," he said. "I consider Montreal to be one of the great cities in North America. But I also have had a life-long dream to be an owner. This fulfills my dream."

Allen said he would concentrate on public relations to improve the Alouettes' image. "I will go door to door if I have to," he said.

He denied that he would try to raid the NFL for players. He said it made better sense to improve the quality of the Canadian players on the team. CFL clubs are allowed to have 15 U.S. players, 19 Canadian.

Among the U.S. players Allen is getting are receivers James Scott and Billy (White Shoes) Johnson, quarterback Vince Ferragamo, running back David Overstreet and linebacker Tom Cousineau. Cousineau, however, wants to play in the NFL next year and Montreal officials have estimated it would take a $600,000 contract to keep him.

Skalbania said he first thought of talking to Allen four days ago while on a beach in Hawaii. The two worked out details Thursday during a meeting in Toronto.

"This is the start of a new era here," Skalbania said. "The try, try again era."