Wheat firmed, although harvest pressure in key exporting countries across the northern hemisphere kept a lid on prices.

The most-active corn contract on the Chicago Board Of Trade  was flat at $4.31-1/2 a bushel, as of 0257 GMT, having climbed 1.1% in the previous session.

Wheat was up 0.3% at $4.88-1/2 a bushel, having closed unchanged on Tuesday, and soybeans were up 0.1% at $9.04-1/2 a bushel after closing down for the last two days.

"The corn market is finding a floor with concerns over dry weather following planting delays," said Phin Ziebell, agribusiness economist, National Australia Bank.

"The late wet planting and dry weather could result in yield losses." The U.S. Department of Agriculture (USDA) reported that 57% of U.S. corn was in good-to-excellent condition, down from 58% last week and below analysts' expectations that it would stay at 58%. Soybeans held steady at 54%.

The wheat market is being weighed down by harvest of a bumper crop in the Black Sea region and North America.

U.S. Agriculture Secretary Sonny Perdue announced that the U.S. government will pay farmers hurt by President Donald Trump's trade war with China a minimum of $15 per acre under an aid package to be unveiled before the end of this week.

Commodity funds were net sellers of CBOT wheat, soybean and soymeal contracts on Tuesday, traders said, and net buyers of corn and soyoil contracts.