The most active corn contract for December delivery went down 4 cents, or 1.06 percent to settle at 3.7325 U.S. dollars per bushel. December wheat declined 4.5 cents, or 0.88 percent to 5.0575 dollars per bushel. January soybeans were down 14 cents, or 1.5 percent to 9.17 dollars per bushel.
CBOT brokers estimated that funds sold 2,500 contracts of corn, 1,000 contracts of wheat and 4,500 contracts of soybeans.
The latest agricultural supply and demand estimates report released Friday by the U.S. Department of Agriculture (USDA) lowered 2019/20 U.S. corn production outlook and ending stocks, pushing up corn prices.
However, corn futures fell on Monday as traders locked in profits.
CBOT soybeans went down for the second straight session after fresh export sales had boosted the oil seed prices on Thursday.
The USDA confirmed on Thursday that private exporters sold 136,000 metric tons of U.S. soybeans to China for delivery during the 2019/20 marketing year.
Also in Friday's supply and demand estimates report, the USDA slightly lowered domestic soybean production, reduced crush, and predicted higher ending stocks, which surprised the market and triggered the fall of CBOT soybean prices in the past two sessions.