It was a tough day in the CME Group corn, soybean and wheat pits.

At the close, the December 2010 corn futures contract was 29 cents lower at $5.26 1/2 per bushel, while January soybeans were 66 3/4 cents lower at $12.19 3/4, according to Barchart.com. December wheat ended the day 46 1/2 cents lower at $6.26 1/4 per bushel.

Fears that China is going to raise interest rates fueled Tuesday's sell-off in the grains, a move that some analysts say could affect how much Chinese buyers might pay for grain in the future. Currently, China accounts for almost 2/3 of all U.S. soybeans sold on the export market, according to a report from Dow Jones Newswires.