Chicago corn and wheat futures declined on Wednesday, following as Wall Street equity markets fell sharply on fears of the coronavirus causing a global recession and a lack of immediate US measures to counter the economic fallout.

Soyabean futures turned lower, erasing early advances tied to a pick-up in export demand for US soya.

Chicago Board of Trade May corn futures settled down 3 cents at $3.74-1/2 per bushel. May wheat ended down 9-1/2 cents at $5.12-3/4 a bushel and May soyabeans finished down 3 cents at $8.73-1/4 a bushel.

"With the crude oil down and equity markets down, it's just hard to make any type of a positive fundamental case for any of these grains," said Brian Hoops, president of Midwest Market Solutions.

A lack of details from the Trump Administration regarding its plans for fiscal stimulus, and partisan wrangling in Washington, added further unknowns to the mix.

CBOT soyabean futures drew early support when the US Department of Agriculture confirmed private sales of 194,000 tonnes of US soyabeans to unknown destinations, the third such soyabean sales announcement in as many days.

But the declines in equity markets overshadowed the export news.

The US Energy Information Administration said US ethanol stockpiles last week fell to 24.33 million barrels, backing down from the previous week's record high, while output of the corn-based fuel fell to 1.04 million barrels per day.