NOTE: The US Federal Reserve's two-day policy meeting concludes with an interest rate decision at 1 p.m. CDT (1800 GMT).
Friday is the last trading day for CBOT October options.
WHEAT - Down 2 to 3 cents per bushel Lower in sideways trade; following early weakness in soybeans and corn.
The USDA said private exporters sold 145,000 tonnes of US hard red winter wheat to Morocco for 2016/17 delivery.
CBOT December soft red winter wheat last down 2-1/4 cents at $4.03-3/4 per bushel; K.C. December hard red winter wheat down 2-1/4 cents at $4.16-1/4; MGEX December spring wheat down 1-1/4 cents at $4.90.
CORN - Down 1 to 2 cents per bushel Lower in light profit-taking following a three-session advance, with additional pressure from the expanding US harvest. CBOT December corn held just above its 50-day moving average near $3.37 overnight.
The USDA said private exporters sold 116,000 tonnes of US grain sorghum to unknown destinations for 2016/17 delivery.
China's National Grain Trade Center reported sales of 203,371 tonnes of 2014 corn at a state reserves auction, representing 20 percent of the 1.02 million tonnes of corn available.
CBOT December corn last down 1-3/4 cents at $3.38-3/4 per bushel.
SOYBEANS - Down 2 to 4 cents per bushel Lower on profit-taking following a four-session climb, and on softening cash basis values in some locations as the US soy harvest gets under way in the Midwest. Fresh export sales may lend support.
The CBOT November soybean contract traded on both sides of its 50-day moving average near $9.87 overnight.
The USDA said private exporters sold a total of 364,000 tonnes of US soybeans in the last day for 2016/17 delivery, including 120,000 tonnes to China, 118,000 tonnes to Taiwan and 126,000 tonnes to unknown destinations.
Malaysian palm oil futures fell, halting a three-session climb, on profit-taking and a weaker export outlook.
CBOT November soybeans last down 3 cents at $9.86-3/4 per bushel.