Running back John Riggins, the most valuable player in the Super Bowl, yesterday signed a multiyear contract with the Redskins that it was learned guarantees him about $1.5 million in the next two years.

"John Riggins will spend the rest of his playing days with the Washington Redskins," said owner Jack Kent Cooke, soon after Riggins, 33, agreed to terms in a meeting at Cooke's estate in Middleburg, Va. "He wants to stay, and I want him to stay."

Other than announcing that Riggins signed a multiyear contract, the Redskins declined to provide any details. Last week Riggins had received an offer from the Michigan Panthers of the new U.S. Football League, which two sources put at $2.5 million for three years guaranteed. The USFL's season begins Sunday.

"This is what I always wanted and I'm glad, real glad," Riggins said in a statement the team released. He was unavailable for further comment.

According to sources, the guaranteed money includes base salary and any signing bonus, which together total about $1.5 million. The length of the contract was unclear, as was its payment schedule.

"You can speculate all you want to," Cooke said. "It will be impure speculation fraught with guesses and will be far wide of the mark. No sir, that is John Riggins' business and my business. It is none of your bloody business."

With the new contract, Riggins becomes one of the highest-paid players in the NFL. It puts him in the same range as Houston quarterback Archie Manning, Chicago running back Walter Payton and Cleveland linebacker Tom Cousineau.

When Riggins, who is seventh in NFL career rushing, played out his option year with the Redskins in 1982, he was the team's highest-paid player, at $330,000. He signed a five-year, $1.5-million contract with the team in 1976, but sat out the 1980 season in a salary dispute because he wanted the final two years of the contract guaranteed.

He set a Super Bowl record with his 166 yards in 38 carries when the Redskins defeated the Miami Dolphins, 27-17, at Pasadena, Calif., Jan. 30 in Super Bowl XVII.

Sixteen players became free agents from that championship team, including Riggins and starting linebacker Rich Milot, who Wednesday signed a four-year contract worth more than $850,000. Milot had an offer from the USFL's Philadelphia Stars, and his new Redskin contract provides indirect guarantees against injury on or off the field.

Cooke said the USFL's offer did not affect his offer to Riggins.

"I was not remotely interested in what he allegedly was offered and he never once brought it up," Cooke said. "Maybe, once yesterday and once today, I mentioned 'The Other League.' But it was only in passing. We were talking Redskins. John Riggins was not auctioning himself."

In Bloomfield Hills, Mich., Shire Rothbart, vice president and treasurer of the USFL's Panthers, said Riggins called him late in the afternoon to inform him he had agreed to remain in Washington.

"The man is a gentleman. He treated us very well," Rothbart said. "I'm glad he made a deal that's a good deal for him, and I wish him nothing but the best."

Rothbart refused to discuss the Panthers' offer. "He (Riggins) knows how to add and subtract very well. He's a bright young man. He's a hot football property right now and he wanted to maximize his value. I don't blame him one bit at all."

In Washington, Jim Gould, president of the USFL's Federals, said a representative of Riggins approached him and said if the team made Riggins an offer, he would "look at it."

Gould said, "We didn't even make him an offer. He's a great asset for the town, and I'm just glad he's staying in Washington. The only reason we would have made an offer was to keep him in Washington."

The USFL rights to Riggins recently were obtained by Michigan from the Boston Breakers. All players drafted by the NFL from 1971-82 were allocated randomly by computer to the 12 USFL franchises. Riggins was a first-round pick of the New York Jets in 1971 and played five seasons for them before signing as a free agent with the Redskins in June 1976. Jim Spavital, his backfield coach with the Jets, is Michigan's general manager.

Riggins had received the Panthers' offer Friday and yesterday was his third day of meetings with the Redskins. He had talked with General Manager Bobby Beathard Tuesday night, and on Wednesday met with Cooke for more than two hours, according to Cooke.

"I looked right at John and said, 'You're going to stay a Redskin, and that's that,' " Cooke said. "He understood exactly what I meant. He looked at me and while he didn't say a word, his eyes did. They said, 'I believe you.' At the same time, he wasn't capitulating just yet. In that meeting, we wound up with a good idea of where we'd go."

Yesterday, Cooke said, Riggins returned around 12:30, and they reached compromises by 2.

As Riggins started to drive away on a gravel path from Cooke's courtyard, Cooke said Riggins turned back to him and said, "Mr. Cooke, next stop, Tampa Bay."

After mentioning the site of Super Bowl XVIII, Riggins waved goodbye.