U.S. business executives in Moscow for an annual meeting of the U.S.-U.S.S.R. Trade and Economic Council expressed optimism Wednesday about Moscow's latest moves toward a market-oriented economy.

"Anything they do is going to help, and this will hopefully accelerate the process toward fluid market conditions in the Soviet Union," said Dwayne Andreas, chairman of Archer-Daniels-Midland, based in Decatur, Ill."Eventually I think their economic reform will succeed. I just hope it's not too slow," added Mr. Andreas who retires today as co-chairman of the council, after seven years at the helm.

The Kremlin plans to announce a new plan today that is expected to reverse the country's slide into a worsening economic crisis.

Aspects of the new plan were unveiled Wednesday by Leonid Abalkin, a deputy prime minister, who called for the "speeding up of radical reform to a regulated market."

Mr. Abalkin emphasized that there must be "social protection" against rapid price increases.

William Forrester, president of the U.S.-U.S.S.R. Council that has offices in New York and Moscow, also was enthusiastic about the plan, which establishes new laws governing foreign investment, joint ventures, free trade zones, banking, taxation, customs and most importantly, prices.

"The more market-oriented this economy becomes, the easier it will be more American business to operate here," he said.

The Soviets prefer a gradual phasing-in of market policies, emphasizing social guarantees for the country's disgruntled population of 285 million.

"The rising of prices is unadvised in the current state of the economy," said Yuri Maslyukov, a deputy prime minister.

Shortages are widespread in all sectors of the economy, and their is speculation that sudden price hikes in food and other goods would invite chaos. These price increases are expected to begin at the beginning of 1991.

Gennady Filshin, secretary of the parliamentary planning and budget

commission, said the new plan is asking the Soviet population to agree to a 100 percent to 200 percent increase in prices. "I do not think the people will accept that," he said.

Today is expected to see an historic session of the Supreme Soviet, the government's parliament, over the new economic plan. Many anticipate a heated debate.