A rallying U.S. Dollar index sent grain futures downhill overnight, setting the stage for a lower open to Wednesday's CME Group trade, sources say.

Early calls for the grains are corn 3-5 cents lower, soybeans 6-10 cents lower and wheat 6-10 cents lower, according to private sources.

In overnight trading, nearby corn traded 3 1/2 cents to $7.04 per bushel while nearby soybeans were 7 cents lower at $13.41 3/4, according to Barchart.com. Nearby wheat was 7 cents lower at $6.74 1/4 per bushel.

An overnight rally in the U.S. Dollar index is primarily behind the expected lower start to Wednesday's grain trade, according to a Dow Jones Newswires report.

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