Chicago Board of Trade (CBOT) grains futures closed lower on Monday with soybean futures falling slightly despite export demand and uncertainty about yield prospects.

Corn fell on expectations of continued, burdensome U.S. supplies, and wheat sagged on technical selling.

The most active corn contract for December delivery dropped 3.25 cents, or 0.92 percent, to 3.515 dollars per bushel. December wheat delivery fell 5.5 cent, or 1.22 percent, to 4.435 dollars per bushel. November soybeans went down one cent, or 0.1 percent, to 9.6775 dollars per bushel.

CBOT floor brokers report that funds have sold 4,300 contracts of corn and 3,200 contracts of wheat, while buying a net 2,100 contracts of soybeans. Funds early sold 2,000 contracts of soybeans.

For the week ending Sept. 14, U.S. private traders has exported 26.5 million bushels of corn, 17 million bushels of wheat, and 34.1 million of soybeans during the 2017/2018 marketing year, according to data released Monday by the United States Department of Agriculture.