Chicago Board of Trade (CBOT) grains futures closed mixed on Wednesday with corn posting significant gains on fund buying.

The most active corn contract for July delivery rose five cents, or 1.36 percent, to 3.72 dollars per bushel. July wheat delivery was down 0.25 cent, or 0.06 percent, to close at 4.2925 dollars per bushel. July soybeans went up 3.25 cents, or 0.36 percent, to 9.16 dollars per bushel.

Analysts contributed the rise of corn futures to the latest U.S. Department of Agriculture report, which said only 65 percent of the crop could be rated as good-to-excellent, down from 72 percent a year ago.

Active funds reportedly took the opportunity to buy 13,000 contracts of corn during the session, thus pushing up its price.

Soybean followed the rise, but was limited to moderate gains, as top soybean importer China reported poor soy crush margins.

Wheat futures went down slightly, following Egypt's order of 180,000 metric tons of wheat from Russia and Romania.