Industrialist Armand Hammer yesterday predicted that the new Soviet-American cultural accord will lead to "a very intensive program of exchanges," beyond the previously announced swap of paintings between Soviet and American museums. It was also announced that the exhibit of paintings from Soviet collections will open at the National Gallery here on May 1.

Hammer also said that at least 10 "major" performing arts groups from each of the two countries are expected to tour during the three-year course of the treaty, signed last month in Geneva. Negotiations for these visits are already under way, he said. And among the Soviet organizations that may come here are the Bolshoi Ballet, the Bolshoi Opera and the Moiseyev dancers. He would not say which American organizations might reciprocate.

The latest development was revealed during a wide-ranging conference phone call that included Hammer, president of Occidental Petroleum Corp.; J. Carter Brown, director of the National Gallery of Art; Philippe de Montebello, director of New York's Metropolitan Museum of Art; and Valentine Kamenev, Soviet consul general in San Francisco. The contract arranging the art shows was signed in Moscow earlier yesterday.

The first product of the accord will be the opening on Feb. 1 at Leningrad's Hermitage Museum of a collection of 40 Impressionist and Post-Impressionist paintings from the National Gallery. Later in the year, an equal number of paintings from the same artistic schools, belonging to the Hermitage and Moscow's Pushkin Museum, will go on view in the United States -- beginning at the National Gallery. From there it will travel to the Los Angeles County Museum of Art, starting July 2, and open in New York on Sept. 3.

In addition, 113 works from the Armand Hammer collection will be mounted at the Hermitage in mid-March and will then go on to the Pushkin Museum and tour other Soviet cities.

Hammer, during yesterday's conference call, declared the Geneva Summit to have been "a great success even though there was no agreement on armaments." Hammer, who has known Soviet leaders going back to Lenin, added, "The two men President Reagan and Soviet leader Mikhail Gorbachev became friends. They made a beginning where they can trust each other and come to agreement on armaments." Later he remarked, "I think the threat of a nuclear holocaust is largely removed."

Brown said he had just spoken with a National Gallery curator in the Soviet Union, negotiating on the contents of the Hermitage show. "He said he encountered an attitude of excitement and euphoria," Brown reported.

The exchange was announced in Moscow by Hammer on Dec. 13. The show coming here will largely duplicate an exhibition that appeared last summer in Lugano, Switzerland, though about 10 paintings will be substituted, according to Brown, "largely since some of the ones in Lugano have already been shown in the United States." Because the exhibition had already been assembled and catalogued, it was possible to get the new cultural treaty off to a quick start, Brown said.

The Soviet paintings include works by Pablo Picasso, Claude Monet, Vincent van Gogh, Paul Gauguin, Henri Matisse, Paul Ce'zanne and Pierre Auguste Renoir. There will be seven Ce'zannes and four Gauguins, all said to be of top quality.

Many of the paintings were acquired in Paris by two sophisticated Russian collectors, Ivan Morozov and Sergei Shuchukin. Following the Russian Revolution, the collections were nationalized.

The selection from the National Gallery that will go to Russia is not yet resolved. But according to the gallery's information officer, Neill Heath, at least four are "pretty definite" -- Renoir's "Young Spanish Woman with a Guitar," Odilon Redon's "Flowers in a Vase," Berthe Morisot's "The Sisters" and Fre'de'ric Bazille's "Negro Girl With Peonies." Otherwise, said Brown, "The list will be subject to some fine-tuning." Brown discussed the possibility of including some American painters, like Thomas Eakins and Whistler.

After the conference call, Brown said that the prospect of having the show had been in the works for some time. "We foresaw that if anything came of Geneva it would be a cultural agreement," he said.

His initial reaction to the prospect of the Lugano show was indifference, he said, partly because impressive examples of such paintings from the Soviet museums have already been exhibited here.

"I was sent the catalogue," he recalled, "and hardly even opened it.

"But when I finally did," Brown explained, "it forced me back to that old rule: Quality is its own reward. To ignore these paintings is like going to a symphony orchestra and saying that because Beethoven is on the program you're not interested."