By Naveen Thukral
SINGAPORE, Aug 12 (Reuters) - Chicago soybeans slid on Tuesday, giving up some gains from the previous session, as expectations of a bumper U.S. harvest weighed on prices.
The drop erased part of the legume's Monday gains which were sparked by U.S. President Donald Trump's remarks that he hoped China would quadruple its soybean purchases.
The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 fell 1.1% to $10.00 a bushel, as of 0403 GMT, after climbing nearly 2.5% on Monday.
"Trump's statement supported prices in the last session but reality is that U.S. is losing market share in China," said one oilseed trader in Singapore.
Corn and wheat eased as traders squared their positions ahead of the monthly U.S. Department of Agriculture (USDA) supply and demand report, which is expected to show plentiful supplies.
Corn Cv1 lost 0.8% to $4.04-1/2 a bushel and wheat Wv1 shed 0.5% to $5.12-1/4 a bushel.
U.S. soybean prices jumped to a two-week high on Monday after Trump urged China, the world's biggest soybean importer, to quadruple its purchases ahead of a tariff truce deadline, though analysts questioned the feasibility of any such deal.
China has not yet pre-purchased soybeans from the upcoming U.S. harvest amid trade tensions with Washington, an unusual delay that has fuelled concerns among U.S. farmers and traders as the harvest export season approaches.
On Monday, Trump signed an executive order extending a tariff truce with China by another 90 days, with only hours to go before U.S. tariffs on Chinese goods were due to snap back to triple-digit rates.
Condition ratings for U.S. corn and soybean crops eased in a weekly USDA report on Monday, though farmers were still expected to harvest large crops.
The USDA rated 72% of the corn crop as being in good or excellent shape as of Sunday, down from 73% last week. It was the highest rating for this time of year since 2016.
The soybean crop was rated 68% good to excellent, down from 69% last week and the same as a year ago.
Commodity funds were net buyers of CBOT soybean and soymeal future contracts on Monday and net sellers of corn, wheat and soyoil, traders said. COMFUND/CBT