CHICAGO (Dow Jones)--Chicago Board of Trade corn futures are expected to open steady to slightly higher Wednesday, after a firm dollar thwarted an overnight rally.

In overnight trade, May corn was up 3/4 cent to $3.56 1/4 per bushel and July corn was up 1/2 cent to $3.65 3/4.

The market is expected to be more stable Wednesday after wide swings to start the week. Prices fell sharply on Monday but regained some lost ground Tuesday.

Prices had been up a few cents in overnight trade but retreated when the dollar firmed thanks to renewed concerns about Greece's debt problems and the Euro, analysts said.

Farmers' good start to the planting season is also expected to limit any gains. Shawn McCambridge, senior grains analyst for Prudential Bache, said "we're seeing ideal planting weather into the weekend." Rains in the forecast for this weekend, while a disruption for farmers, are ultimately beneficial--McCambridge said that without the rains, there would be increasing talk of soils becoming too dry.

McCambridge said the U.S. seems on track to have about half the corn crop planted by the end of the month, which would be "an extremely good start."

But a floor trader said it is still early in the season to push the market much below current levels. Once the crop is securely planted, downward seasonal trends could become a stronger factor, he said.

Demand remains lackluster, and could be behind the pace needed to meet current USDA expectations, McCambridge said. A trader added that the market does have some underlying support from China demand for distillers dried grain, the ethanol byproduct that is used for feed.

The next downside price objective for the bears is to push and close prices below solid technical support at the April low of $3.55, a technical analyst said. The b next upside price objective is to push and close prices above solid technical resistance at last week's high of $3.74 3/4 a bushel.

First resistance for July corn is seen at Tuesday's high of $3.66 1/4 and then at $3.70, the technical analyst said. First support is seen at $3.60 and then at this week's low of $3.57.

-By Ian Berry, Dow Jones Newswires; 312-341-5778;