CHICAGO (Dow Jones)--Chicago Board of Trade corn futures are expected to open slightly lower Friday as benign weather weighs on the market ahead of a three-day holiday weekend.

Corn is called 1 to 3 cents lower. In overnight trade, September corn was down 3 cents to $3.08 per bushel, December corn was down 2 1/4 cents to $3.13 1/2 and March 2010 corn was down 2 cents to $3.27.

While meteorologists noted the emergence of a potential, far-off frost threat in the long-range forecast Thursday, that threat has since disappeared, and the Midwest again looks like it will not see frost for at least the next two weeks.

"The weather we've been seeing has been relatively ideal," a trader said, noting warmer conditions that should boost the late-developing crop.

That will keep the market under pressure, analysts said. However, with the Labor Day weekend approaching, analysts say traders will remain reluctant to push the market too much lower.

Analysts also note that basis, or the difference between cash and futures prices, has been tight as farmers hold onto grain. There were 146 deliveries reported against the September futures contract Friday morning.

Traders and analysts say the market could pick up more demand as it closes in on $3 per bushel.

Outside markets appear to be a mixed influence, traders said. Farm Futures said that without any compelling fundamental news Friday, the market could be "vulnerable to chart signals and nervous outside markets."

The next upside price objective is to push December prices above solid technical resistance at last week's high of $3.37 1/2 a bushel, a technical analyst said. The next downside price objective for the bears is to push and close prices below major psychological support at $3.00 a bushel.

First resistance for December corn is seen at $3.20 and then at $3.25. First support is seen at Thursday's low of $3.11 1/2 and then at $3.08.

The Korea Feed Association purchased 55,000 metric tons of corn from Marubeni for arrival March 15 in a tender concluded late Thursday, a KFA official said.

The corn was purchased at $197.50/ton if it is of U.S. origin and $194.70/ton if it is of South American origin, both on a cost-and-freight basis, he said.

In other international news, China's corn prices are likely to rise further next year on declining output and rising demand, a senior industry participant said Friday.

The country's total corn output in 2009 is expected to fall 19.97 million metric tons or 12% to 145.94 million tons due to an ongoing serious drought, Li Qiang, chairman of Shanghai JCI, a commodities consultancy firm, said during a conference.

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