A director of a new U.S.-Soviet effort to help American businesses sell everything from cosmetics to caviar in the Soviet Union says he expects Moscow to relax its limits on foreign ownership of companies early next year.

Current Soviet law requires that joint business ventures be no more than 49 percent foreign owned, but Randy Bregman of Washington-based APCO Associates said he expects this to be liberalized, possibly within the first three months of 1989.APCO is an affiliate of the law firm of Arnold & Porter, which held a news conference Tuesday to announce that APCO had set up a joint venture with INFEKS, a six-month-old Soviet consulting cooperative affiliated with the U.S.S.R. Ministry of Foreign Economic Relations.

New Soviet efforts to open and restructure the country's economy offer "access to a market of 280 million highly educated Soviet consumers with an enormous need for goods and technology," said James Jones, the firm's managing partner.

He said Soviet President Mikhail S. Gorbachev's policies are "setting an exciting new course for East-West business relationships."

Bregman, director of Soviet and East European services for APCO, said the new venture will help American businesses set up joint operations with Soviet cooperatives and other enterprises.

Speaking before a Soviet and U.S. flag and with a direct telephone hookup to Moscow, officials said the partners in the venture would draw up final details and meet with prospective clients later this week.

Bregman said APCO hopes to double the number of U.S.-Soviet ventures by the end of next year. Ten joint U.S.-Soviet business agreements have been concluded to date, along with about 100 Soviet ventures with businesses from other countries, he said.

Bregman said he looks to the day when a Soviet citizen can buy borscht made by Campbell Soup Co. He said Campbell is not one of the companies now involved, but this is an example of the kind of enterprise that might result from the new agreement.

Bregman declined to name companies that might deal with the Soviets through APCO, but he said they include about a dozen companies involved in food processing, pollution control, medical equipment, cosmetics, tourism and telecommunications. One U.S. company even wants to get into caviar production, he said.

Vladimir Gusinsky, INFEKS president, said from Moscow that the Soviet enterprise is part of the economic "perestroika," or restructuring, under way in his country.

"We are looking forward to developing economic relations with U.S. companies," Gusinsky said through a translator who also translated the Washington news conference in Russian over the telephone hookup.

Gusinsky and other INFEKS officials were to arrive in Washington later this week.

APCO President Margery Kraus said the company, which also has set up joint ventures with Japanese and Israeli businesses, would open an office in Moscow early next year.

She said the company would provide "one-stop shopping" for companies wanting to do business in the Soviet Union, charging fees for its services. She said there were no plans for APCO to share in profits of the joint ventures it helps set up.