Chicago soybeans fell on Monday in a pullback after hitting their highest in more than three months earlier in the day, as attention started returning to large South American crops.
Corn rose for a third day, touching its highest since Feb. 24, while wheat firmed slightly after easing in the last session.
The most-active soybean contract on the Chicago Board of Trade (CBOT) was down 0.3 percent at $8.92-3/4 at 1055 GMT after rising to $8.96-3/4 a bushel, matching Friday's peak, which was the highest since Dec. 7.
Most-active corn climbed 0.5 percent to an intraday high of $3.67 a bushel. Most-active wheat gained 0.05 percent to $4.76 a bushel after dropping 0.3 percent on Friday.
Soybeans were pulling back from highs as crude oil fell and with attention returning to large crops arriving on world markets from South America, Matt Ammermann of INTL FC Stone said.
"Fundamentally without any reason to sustain this price action, to me soybeans have the most downside potential," Ammermann said.
Soybeans had been bolstered recently by gains in Brazil's currency, the real , which make Brazilian soybeans more expensive on world markets and could boost U.S. sales because the United States competes with Brazil for exports.
But the real slipped on Monday, possibly lessening the export handicap, while the latest estimates from Brazil underlined a giant soybean crop is arriving on world markets.
Brazil's current 2015/2016 soybean crop has risen to a record 101.18 million tonnes, from 100.93 million estimated in February due to gains in area planted and yields, the government's crop supply agency Conab said on Thursday.
Meanwhile, commodity funds bought an estimated net 7,000 CBOT soybean contracts on Friday, trade sources said.
The wheat market is still being supported by concerns over dry weather in U.S. Plains states, although gains have been capped by ample world supplies, dealers said.
Corn remained supported by hopes of brisk U.S. exports.
On Friday, the U.S. Department of Agriculture said Japan bought 170,800 tonnes of U.S. corn. A day earlier, the agency reported the largest weekly U.S. corn export sales since November.