U.S. business spokesmen foresee relatively little commercial impact if President Bush and Soviet President Mikhail Gorbachev do not sign a trade accord this week.

But some American business officials warn that failure to sign a trade agreement will have a "psychological" effect on U.S.-Soviet dealings. It could reinforce the Soviet tendency to trade primarily with Western Europe, one official said.U.S.-Soviet talks on an investment agreement and a tax treaty also might be affected if a U.S.-Soviet trade accord becomes stalled, others said.

Oleg Klimov, chairman of Exportkhleb, the Soviet grains trading agency, meanwhile hinted in Moscow that Mr. Gorbachev might not sign a new grains trade agreement with the United States unless a general trade pact is signed this week.

The grains pact, which would increase from 9 million to 10 million metric tons a year the minimum Soviet purchases of U.S. grains and soybeans, is ready for signature at the Bush-Gorbachev summit.

But even if the Soviets carried out this threat, it might not have much, if any, market impact, suggested William Archey, the U.S. Chamber of Commerce's vice president, international.

He cited "the very satisfactory relations" the Soviets have with U.S.

grains exporters. "I don't think they'd want to disrupt that," he said.

Leroy Watson, a National Grange executive, also was skeptical of the implied Soviet threat. On balance, he said, the new grains pact is more important to the Soviets than to the United States.

The Soviets, he said, need a stable supply of grains, and the United States is the "the world's most stable supplier."

The generally subdued reaction of U.S. business spokesmen to the prospect that Mr. Bush and Mr. Gorbachev may not sign a general trade accord partly reflects the present economic disarray in the Soviet Union.

Declining Soviet creditworthiness is making the already limited short-term prospects of U.S.-Soviet trade even more questionable, said Eugene Milosh, president of the American Association of Exporters and Importers.

A U.S.-Soviet trade pact "would not solve the Soviet credit crunch," he noted.

A trade agreement, said Mr. Archey, would be "an extremely important first step." But, he added, it would be subject to congressional approval, and a majority of the Senate is on record opposing new trade benefits for the Soviet Union at this time.

He, too, pointed to the Soviet Union's economic problems as a trade deterrent.

Under U.S. law, the Soviet Union can qualify for lower U.S. tariffs only if the president signs both a trade agreement and a waiver of the Jackson-Vanik amendment.

That amendment, part of the 1974 trade law, links "most-favored-nation" treatment, or lower tariffs, to Soviet emigration policies.

If the president declines to sign the two documents, he appears likely to

draw more criticism from some business circles, especially because of his decision last week to renew most-favored-nation benefits for China.

"If it is important to have normal relations with China, all those reasons apply to the Soviet Union, probably . . . in spades," said James Montgomery, executive director of the East-West Forum, a Washington, D.C.-based research and advocacy group.