CHICAGO, June 28 (Xinhua) -- Chicago Board of Trade (CBOT) agricultural commodities closed lower on Thursday, with corn and soybean futures edging lower ahead of a key U.S. governmental crop report due on Friday expected to raise estimates of corn and soybean plantings in 2018.

The most active corn contract for July delivery went down 7.5 cents, or 2.13 percent to close at 3.45 dollars per bushel. September wheat delivery fell 5 cents, or 1.02 percent to close at 4.835 dollars per bushel. November soybean delivery went down 5.5 cents, or 0.62 percent to close at 8.835 dollars per bushel.

Wheat also eased, pressured by an accelerating U.S. winter crop harvest and reports of higher-than-expected yields in some areas.

Favorable crop weather around the U.S. farm belt weighed on grain markets in general, but declines were limited by U.S. Department of Agriculture (USDA) weekly data showing good export sales following recent price declines.

According to USDA Weekly Export Sales report released on Thursday, U.S. exporters sold 33 million bushels of corn, versus 7 million the week prior; 13 million bushels of soybeans, versus 11 million the week before, and 21 million bushels of wheat, versus 17 million in the last week.