Washington Redskin coach and general manager George Allen has signed a new four-year contract for a salary of approximately $250,000 a year, doubling his pay. The Washington Post learned last night.

Allen had one season remaining on a seven-year $125,000 a season contract that he signed when he came to Washington from the Los Angeles Rams in 1971.

It was learned that under the agreement Allen signed this week he will receive a $125,000-a-year raise, which go into effect this season. The entire package, worth $1.25 million, will carry the 55-year-old Allen through the 1981 season.

The new contract is believed to put Allen at the same salary scale as the two highest paid coaches in the National Football League - John McKay of Tampa Bay and Chuck Fairbanks of New England.

Allen's signing culminated nearly a year of negotiations between the coach's attorney, Ed Hookstratten, and the president of the Redskins, Edward Bennett Williams. Williams is recovering from recent abdominal surgery.

While Allen still had a year remaining on his contract his being in a lame-duck status during the 1977 season could have had an adverse affect on the squad.

It is customary for a club to reward a coach as successful as Allen with a new contract before the old one expires.

If the Redskins had not signaled their appreciation of his accomplishments here with a salary to at least match that of some unproven coaches from college ranks it would have been a message to the players: Allen might be just going through the motions this season preparatory to considering other teams, offers for 1978.

In fact, at one phase of the negotiations, some observers close to the situation speculated that Allen might not honor the last year of his contract.

Some older players voiced doubts that they would return if Allen did not. They pointed out that under a new coach they might have to prove themselves all over again in a training camp so rigorous they could not save anything for late-season games.

Now the Redskins will be going to camp Saturday with the coach knowing he is highly esteemed by management and the players knowing he will be around at least for several more years to head up the program.

Allen's first contract was flattering when he signed it in 1971. There were fringe benefits such a performance bonuses and even the privilege of buying stock, which the coach did not exercise.

But since then, such coaches as Fairbanks, Dick Vermeil of Philadelphia, and McKay came into pro ball direct from college jobs with salaries ranging from $185,000 a year for Vermeil to about $250,000 for Fairbanks as well as McKay.

Allen was represented in the negotiation of both contracts with the Redskins by Los Angeles attorney Hookstratten, who also represented McKay and Vermeil.

Although the Redskins were eliminated in the first round of last season's playoffs, Allen did one of his best coaching jobs. He never had a losing season, at Los Angeles or Washington.

The Redskins beat the St. Louis Cardinals, Eagles, New York jets and Dallas Cowboys in their last four games to win a playoff as the wild card team in the NFC with a 10-4 record. They ran out of gas against the Minnesota Vikings in the first game of the playoffs.

Allen's Redskins have missed making postseason play in only one of his six years here, while compiling a 58-25-1 recors. His first head coacing job was the Rams, who had seven straight losing season before that. Allen had an 8-6 record his first year and left Los Angeles with a 97-38-5 record.