SINGAPORE: US corn futures fell for a third straight session on Wednesday as farmers rapidly advanced harvesting in the United States and added to global supplies which are already ample.

Wheat gained ground after Tuesday's drop, while soybeans ticked lower.

"Market chatter about corn crop upgrades weighed on the mood," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.

"As is the gathering harvest of northern summer crops, though have passed the point where US corn prices usually make their seasonal low."

The most-active corn contract on the Chicago Board Of Trade (CBOT) slid 0.1% to $5.37 a bushel, as of 0348 GMT, having closed down 0.6% in the previous session.

Soybeans were down 0.1% at $12.49-3/4 a bushel and wheat climbed 0.5% to $7.48-1/2 a bushel.

The US Department of Agriculture (USDA) said on Monday afternoon that corn harvest was 29% complete, ahead of the five-year average of 22% and in line with market expectations.

Private analytics firm IHS Markit Agribusiness estimated US 2021 corn production at 15.085 billion bushels, above the USDA's forecast for 14.996 billion.

The USDA said 47% of the winter wheat crop was planted, 1 percentage point ahead of the five-year average.

Soft wheat exports from the European Union in the 2021/22 season that started in July had reached 8.07 million tonnes by Oct. 3, data published by the European Commission on Tuesday showed.

That was up from 5.56 million tonnes by the same week in 2020/21.

The Russian agricultural ministry has cut its grain export forecast for this harvest year to 45-48 million tonnes, the Interfax news agency cited the ministry as saying on Tuesday, down from a previous estimate of 51 million tonnes.

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