CHICAGO (Dow Jones)--Chicago Board of Trade corn futures are expected to open steady to slightly lower Wednesday as big crop expectations and a lack of supportive news keep the market under pressure.

Corn is called mixed to 2 cents lower. In overnight trade, September corn was down 1 3/4 cents to $3.19 3/4 per bushel and December corn was down 1 1/4 cents to $3.25 1/2.

Widespread expectations that the corn crop is poised to challenge the U.S. record yield of 160.4 bushels per acre is weighing on prices, traders said.

"Fundamentally, the corn crop is developing into what is expected to be a whopper," Country Hedging analyst Ami L. Heesch said in a morning commentary.

But traders and analysts also note that the slow pace of the crop is limiting the bearish sentiment, at least for now. The crop is far behind schedule, especially in Illinois, a key corn producer, and analysts say corn will need more time than usual before the first frost arrives to meet its full potential.

The weather is seen as benign, with no frost threat on the horizon. But bulls point out that with cool temperatures expected across the Midwest through at least Sunday, corn development will continue to lag.

Analysts said the market had a bearish outside day Tuesday technically, as prices climbed initially before stumbling.

"When Dec. corn did finally make it above Monday's high, there simply seemed to be no real follow-through," said Mike Zuzolo, owner of Global Commodity Analytics and Consulting. "I think this likely caused some good old-fashioned `throw in the towel' type selling-out by longs."

The next upside price objective is to push December prices above solid technical resistance at $3.50 a bushel, a technical analyst said. The next downside price objective for the bears is to push and close prices below solid technical support at last week's low of $3.11 1/2 a bushel.

First resistance for December corn is seen at $3.30 and then at Tuesday's high of $3.37 1/2, the technical analyst said. First support is seen at Tuesday's low of $3.22 1/2 and then at $3.20.

Outside macro markets appear to be offering little direction Wednesday morning, traders said.

In export news, South Korea's Nonghyup Feed Inc. has bought 110,000 metric tons of corn for March delivery in a tender concluded late Tuesday, a trader with the company said Wednesday.

A trader said weekly export sales to be reported Thursday should be strong, at above 1 million bushels.

Also, Taiwan's Maize Industry Procurement Association Tuesday purchased 60,000 metric tons of Brazil-origin corn from U.S.-based trading firm Agrex for delivery in October, an MIPA official said Wednesday.

-By Ian Berry, Dow Jones Newswires; 312-341-5778; ian.berry@dowjones.com