Chicago agricultural commodity futures fell Thursday, as sluggish export sales and favorable weather pressured the trading most of the day. The most active corn contract for December delivery fell 18.75 U.S. cents, or 3.88 percent, to 4.645 dollars per bushel. December wheat dropped 8.75 cents, or 1.35 percent, to settle at 6.405 dollars per bushel. November soybeans fell 17.25 cents, or 1.32 percent, to 12.8675 dollars per bushel. According to Chicago Mercantile Exchange, corn futures traded sharply lower and the December contract fell to a new low for the week. As of Aug. 15, net weekly export sales came in at 58,200 tons for the current marketing year and 434,400 tons for the next marketing year. Sales of 377,000 tons are needed every week to reach the U.S. Department of Agriculture forecast. Wheat futures traded lower into the closing bell, mostly in line with the weak corn market. Net weekly export sales came in at 494,000 tons for the current marketing year, falling slightly short of traders\' expectation. The soybean market traded lower amid talk of an overbought situation and favorable weather condition in the coming week which features a mix of rainfall and increasing temperatures.