The White House announced a continued waiver Monday of trade restrictions on the Soviet Union, clearing the way for food aid and expanded commercial relations to encourage economic and political reform.

As expected, White House press secretary Marlin Fitzwater said President Bush had decided to extend a six-month waiver that has enabled the Soviets to receive $1 billion in export credit guarantees to buy American grain products.Since 1974, the Jackson-Vanik Amendment has barred U.S. government credits and credit guarantees for the Soviets because of prohibitive emigration laws. Political improvements led Bush in December to order a temporary reprieve.

With renewal of the Jackson-Vanik waiver, administration officials indicated other actions would quickly follow. It also helps improve the climate for a Bush-Gorbachev summit, which could come in late June or July (see story at right).

The move on Jackson-Vanik set the stage for action on Gorbachev's plea for another $1.5 billion in food credits. Though legal complications remain, officials expect Bush to meet at least part of the request, in some form.

Second, it satisfied one condition for most-favored-nation status, which would lower tariffs on exports to the United States and subject trade with the Soviet Union to the same rules applied to 100 other countries.

Bush also was close to meeting a second criterion for favored trade status by moving ahead with ratification of a U.S.-Soviet commercial agreement. Signed a year ago, it has been held up by Soviet delays in passing a promised freedom-of-travel law.

Long-awaited approval of that law on May 20 was an indication Gorbachev not only had swung back to the cause of reform but with increasing urgency was looking to the West to rescue the Soviet economy from collapse.

His desperation to remove distractions and obstacles to Western help was evident in Saturday's resolution of a dispute holding up negotiated cuts in non-nuclear weapons in Europe. The impasse was broken with concessions from the Soviets.

Just as the Jackson-Vanik waiver sets the stage for decisions on trade and aid, arms control breakthrough clears the political air.

Negotiators now will bear down on conclusion of a treaty cutting strategic nuclear arsenals - Bush refused to move forward on that as long as the pact on conventional forces was mired in disagreement - and, in turn, on plans for a summer U.S.-Soviet summit.

All of that bodes well for embattled Gorbachev, who needs not only money from the West, but the kind of dramatic endorsement at home that would come from a high-profile summit in Moscow.