GRAINS-Soy, wheat retreat on US trade uncertainty after tariff ruling

By Tom Polansek

CHICAGO, Feb 23 (Reuters) - U.S. grain and soybean futures reached multi-month highs on Monday before pulling back as traders worried about potential harm to exports following the Supreme Court's decision to strike down President Donald Trump's import tariffs.

Traders have watched U.S. crop exports closely since Trump's trade dispute with China last year halted American soybean sales to the world's biggest importer. In late October, Washington and Beijing reached a trade truce that restarted China's purchases.

Traders are now waiting to see whether countries may back away from U.S. trade deals following the Supreme Court's ruling or retaliate after Trump on Saturday raised a temporary duty to 15% on U.S. imports from all countries.

On Friday, Trump imposed a 10% temporary tariff after the Supreme Court struck down his previous tariff program. He also ordered the start of new investigations under other statutes that officials said could result in additional tariffs affecting many trading partners.

"It's just nervousness," said Don Roose, president of U.S. Commodities in Iowa. "What does it mean for our export demand going forward?"

MARKETS RETREAT FROM MULTI-MONTH HIGHS

Chicago Board of Trade May soybean futures SK26 ended 3-1/2 cents lower at $11.49-3/4 per bushel after advancing earlier to the highest level since November 19.

CBOT May wheat futures WK26 closed down 6-1/2 cents at $5.73-3/4 per bushel after reaching the highest level since July 29. May corn CK26 finished up 1/2 cent at $4.40-1/4 per bushel after rising earlier to the highest level since January 12 at $4.45.

Fund buying supported early gains before worries increased about U.S. exports and traders took profits, analysts said.

Trump on Monday warned countries against backing away from recently negotiated trade deals after the Supreme Court's decision, saying that he would hit them with much higher duties under different trade laws.

“Several other countries ranging from Bangladesh, Indonesia to Vietnam also made deals in various forms to buy U.S. farm goods," a German trader said. "The question is whether these deals will be quietly dropped as the threat of U.S. tariffs disappears.”