Wheat futures slumped after top importer Egypt snubbed the United States in a weekend tender, while soybeans rose as traders bought back some previously sold positions.
Analysts said the corn and soy markets should start the overnight trading session mixed after the United States cut condition ratings for the crops due to heavy rains, as many traders had expected.
The Agriculture Department, in a weekly report, rated 74 percent of U.S. corn as good or excellent, down 2 percentage points and in line with analysts' estimates. The agency rated 72 percent of U.S. soy crop as good or excellent, down 1 percentage point and above analysts' expectations.
Wet weekend weather set the stage for Monday's decline in corn futures as analysts said crops should ultimately benefit from the moisture. Some areas have received too much rain, causing flooding and localized crop damage.
With soybeans, "perhaps a lot of people were overestimating the damage," said Rich Nelson, chief strategist for Allendale in McHenry, Ill.
"Soybeans are still looking tremendous right now."
Front-month corn fell 1.9 percent, or 8-3/4 cents, to $4.44-1/4 a bushel. The contract pulled back after touching a session high of $4.57-3/4, a
level last reached on June 6.
Spot soybeans rose 0.6 percent, or 9 cents, to $14.28 a bushel, off the session high of $14.34-1/2, which was a one-week peak.
A better-than-expected reading for factory activity in China helped underpin soybean futures as the data reassured traders about demand from the world's top importer of the oilseed, analysts said.
"Any time you have good economic news out of China, it's friendly to soybeans because they're such big importers," said Jim Gerlach, president of A/C Trading in Fowler, Indiana.
Egypt said on Saturday that it had bought 180,000 tonnes of Russian and Romanian wheat for shipment Aug. 1-10 and none from the United States.
Spot wheat slipped 0.9 percent, or 5-1/2 cents, to $5.79 a bushel.
Analysts said trading in all the markets should be choppy this week ahead of U.S. crop acreage and quarterly grain stock reports due out on June 30.
