President Bush is considering a shift in United States policy that would open the way to providing credits to the Soviet Union for the purchase of American grain and an expansion of Soviet-American trade, administration officials said yesterday.

As Western European nations rush food supplies to Moscow, the officials said Bush may soon waive on a temporary basis restrictions on Soviet trade that have existed under the Jackson-Vanik amendment to the 1974 U.S. Trade Act. That amendment prohibits preferential lower tariffs or access to U.S. credits to any nation that denies its citizens the right to emigrate.

Until now, the United States has demanded that the Soviet parliament pass a law codifying its liberalized emigration policy before further action could be taken. However, the emigration bill has been stalled in the Supreme Soviet, and officials say it may not be approved soon.

Two senior officials said an option being prepared for Bush would be to waive the Jackson-Vanik amendment on grounds that, even if the emigration law has not been passed, the Soviets have in practice allowed a large number of people to emigrate, particularly Soviet Jews to Israel. One of the officials said the relatively large volume of emigration would mean there may be less objection in the United States to a waiver, at least for a temporary period like a year.

Agriculture Secretary Clayton Yeutter said yesterday that Bush had told him he "is prepared to have the matter fully reconsidered." Yeutter added, "In my view, we should provide credit guarantees to the Soviet Union."

Farm groups and farm state lawmakers have been pressing hard in recent weeks for a shift in policy, saying that the Soviets need credit to purchase American grain, and if they do not get it they will turn to other nations as suppliers.

According to the U.S. Wheat Association, under the U.S.-Soviet Long Term Grain Agreement, the Soviets have pledged to buy about 1.2 million tons of wheat and about 600,000 tons of corn in the final three months of this year. The group said that American refusal to provide credit guarantees may result in the Soviets falling short of their commitment.

Senior Soviet grain officials held meetings at the State Department and Agriculture Department this week to discuss their interest in credits for grain purchases, officials said. Winston Wilson, president of the wheat group, this week criticized the White House for "paralysis" on the issue. Similarly, some legislators from the farm belt this week urged Bush to take action soon.

Although there has been a concerted effort in Western Europe and elsewhere to provide emergency food aid to the Soviet Union, administration officials said there has not yet been a direct request to the Bush administration for such aid.

One official said that the linkage to the emigration bill had seemed like a good approach earlier this year, creating a condition for expanded trade with the United States. However, this official said, "more and more there is a sense here that perhaps the quid pro quo has been overtaken" by events. "The rationale for hanging on to this is eroding quite rapidly.

"The Soviets are clearly shopping for grain," the official said. "Do we want to shut ourselves out of that? "

Even if Bush acts to waive the restrictions, officials said there are many unanswered questions about how food assistance could be distributed in the Soviet Union, where the command economy is collapsing and distribution is a major problem. In some cases, the Soviets have been unable to take advantage of credits already available.