One of the major reasons George Allen has not yet signed his four-year contract extension with the Washington Redskins involves a disagreement over the financial operations of the club, it was learned yesterday.

Sources told The Washington Post that Allen, the head coach and general manager, wants almost total autonomy in the financial control of the football operation, and team president Edward Bennett Williams apparently is unwilling to go along.

After the 1976 season, Williams made a point to say that he wanted to hire a full-time financial watchdog for the club, a role his former executive assistant, David Slattery, held until the later resigned after the 1975 season.

Slattery's job never has been filled. A source said yesterday that Allen now has almost complete control of spending involving the football operation, and that Williams still wants to take a firmer grip in that area.

Allen yesterday insisted, "I don't think there are nay problems" when he was asked if his contract hassle could be resolved. Then why hasn't he signed? he was asked.

"There are some legal things, attorney's stuff," he said. "I don't even wanto to think about it. I just want to have a good week of practice and have good preparation to play the Colts.

"I don't even want to comment (on the contract situation). That's the least of my concerns. I'm a football coach, not a lawyer."

Why, he was asked, was a press conference called last July to announce that he had come to terms on a four-year contract extension?

"You'll have to talk to Mr. Williams about that," Allen said. "He made the announcement."

Allen did not attend that press conference because he was attending funeral services for his mother in Albany, N.Y., although his son George Jr. read a prepared statement from Allen at the session.

William says he does not want to talk about the contract negotiations publicly, and Allen's attorney, Ed Hookstratten of Los Angeles, has not returned reporters' phoen call for the last three days.