A Soviet cultural affairs official said yesterday that there has been no change in the Soviet Union's policy of permitting its artists to fulfill contracts to perform in the U.S.

The U.S.-U.S.S.R. cultural exchange agreement expired Dec. 31, but the officials said a standing agreement is not necessary for the continuation of cultural exchanges. He also said the U.S.S.R. will not object if the U.S. chooses not to continue last fall's negotiations on renewing the agreement.

That agreement would not affect 11 groups traveling from the U.S.S.R. A State Department official said yesterday that "a lot of these things may not be exchanges at all -- they are private, for-profit operations."

The Soviet statement came in the wake of cancellations of four separate U.S. tours by Soviet performers that were scheduled to begin next month -- all under the sponsorship of Columbia Artists Management Inc. (CAMI). CAMI is a major New York-based artists' management and impresario organization.

Samuel M. Niefeld, CAMI vice president, said the losses to his organization and others that were to have hosted the Soviet performers were "in excess of $400,000."

Anatoli M. Dyuzhev, cultural counselor at the Soviet Embassy, said multi-city tours by pianist Lazar Berman and the Moiseyev folk dance company later this year are expected to proceed as scheduled.

Aside from President Carter's Jan. 4 announcement deferring most future cultural exchanges currently under consideration, CAMI and other industry sources suggested three possible reasons for the Soviet cancellations: First, an alleged Soviet demand for U.S. government guarantees that no future defections by Soviet artists in the U.S. would be allowed.

Second, an attempt by the Soviet Union to punish CAMI because of CAMI's co-sponsorship of last summer's tour by the Bolshoi Ballet on which three dancers defected -- including Alexander Godunov. Third, that the Soviet Union is allowing only performers whose loyalty it is sure of to appear here.

Dyuzhev denied that the U.S.S.R. asked the U.S. to guarantee that no more defections will be allowed. "It's impossible," he said, to expect the U.S. government to agree to such request. But CAMI's Niefeld said his office had received a cable Tuesday from the Soviet ministry of culture stating that a tour by a Soviet chorus could not be confirmed both because of President Carter's Jan. 4 speech, and because during negotiations on cultural exchanges in Moscow last November, U.S. officials had refused to provide "guarantees of security" for Soviet artists while in the U.S.

Niefeld said "security" means guarantees against defections.

The State Department official refused to confirm or deny that the U.S.S.R. had made such a request during the exchange negotiations, which the State Department says are not now likely to be reconvened.

Meanwhile, Alexander Dube, a leading New York ballet manager, announced that on Jan. 3 in Moscow he signed final agreements for American ballerina Eleanor D'Antuono to appear in three Soviet cities begining Feb. 3, and for two other dancers from the American Ballet Theatre to perform in the U.S.S.R. for three weeks next May. Dube had negotiated D'Antuono's tour of the U.S.S.R. last year.