The owners of composer Igor Stravinsky's archives today sold the collection to the Paul Sacher Foundation in Basel, Switzerland, for $5.25 million. The price was more than twice what any institution had been willing to pay for the archives as recently as six months ago and $1 million more than the nearest competing offer.

The archives are to be delivered to Switzerland next month.

The music manuscripts, thousands of pieces of correspondence and other documents are considered by many to constitute the world's greatest single collection of documents relating to the creation of 20th-century classical music and the classical performing arts still in private hands.

The owners, the heirs of Igor and Vera Stravinsky, are Stravinsky's three children by a previous wife, a granddaughter and longtime Stravinsky aide and collaborator Robert Craft.

The collection had been hotly sought after by various American institutions during the last 15 years, with some heirs having favored a bid made a year ago by UCLA for $1.5 million and other heirs favoring the University of Texas' $2 million offer.

But a continuing series of legal maneuvers brought by the attorney for the two Stravinsky children who live in America kept the collection from being sold last year--despite a New York court order that it be sold to UCLA.

Industry insiders credited attorney George V. Bobrinskoy of the Chicago law firm of Mayer, Brown & Platt with having forced the price up.

As of Monday morning, there were two bidders left: the Sacher Foundation, which had offered $4.1 million, and representatives of arts patron Frederick R. Koch, who offered $3.75 million. Koch was said to be putting up the funds for a "charitable foundation" to purchase the collection and then loan it to Manhattan's Pierpont Morgan library. The Morgan library confirmed that Koch was the man behind that bid.

On Monday afternoon, the Sacher Foundation asked the heirs to name their price, Sacher's agent, Albi Rosenthal of London, said today.

The heirs declined. Koch's representatives offered $4.25 million.

The heirs finally asked for $5.25 million and Sacher today agreed to that price.

The New York Public Library had been the other major contender for the archives this year. Until earlier this month, it had been attempting to raise funds for the purchase of the collection but ended those efforts when it learned that the Morgan library had a supporter who was prepared to buy the collection.

This afternoon, Vartan Gregorian, president of the public library, criticized the sale because the collection will go to a foreign country and claimed that his institution had not been given an appropriate opportunity to reenter the competition.

Gregorian said, "I cannot believe that there has been so much secrecy, doubletalk and doublespeak in this matter . . . It's sad . . ."

The public library president said he "took a passive role" solely because the Morgan library made it seem the purchase was assured.

Attorney Martin Garbus, representing Craft, said his client was happy with the decision. "I knew Igor and Vera Stravinsky and I know the both would be pleased" by the decision to sell to the Swiss foundation, Garbus said.

Bobrinskoy, speaking for Milene Stravinsky Marion and Soulima Stravinsky, the two children who live in the United States, said, "We are relieved that it's over, and disappointed that the collection could not remain in the U.S."

Among the terms the Sacher Foundation has agreed to are that the collection be made available to scholars and to the public, that it has to be exhibited and that it cannot be resold.

Sacher's agent Rosenthal said that the 77-year-old Sacher and Sacher's wife are the "titular heads" of Hoffman-La Roche. That firm is best known as a pharmaceutical manufacturer and is believed to be one of the largest privately held companies in the world. Rosenthal said he lacked information on the Sacher family's holdings in the company.

Sacher is well known in the music world as a conductor, musicologist and champion of 20th century music. He was a personal friend of Stravinsky's, from whom he once commissioned a score.

The archive is to be housed in a seven-story building that faces the Rhine River and is to be opened to the public, after extensive rebuilding, next year.