CHICAGO (Dow Jones)--Chicago Board of Trade corn futures are expected to open slightly lower Monday amid technical pressure and a lack of any significant weather threat to the heart of the U.S. corn belt.

Corn is called 1 to 2 cents lower. In overnight trade, December corn was down 1 cent to $3.33 per bushel, and March corn was down 1 1/4 cents to $3.45 1/2.

The market could see some follow-through selling to start the week, said Shawn McCambridge, senior grains analyst for Prudential Bache.

"The market is a little bit technically weak after starting to sell off last week," McCambridge.

He added that outside markets are "anemic" and offering little direction. Farm Futures senior editor Bryce Knorr said in a morning commentary that the market opened higher overnight but "reversed direction when stock prices in Asia fell over concerns about the pace of economic growth in the U.S., which sent the dollar higher, weakening most commodity prices."

The trade is eyeing the weather for signs of a frost, which could cut short some of the late-developing crop. McCambridge said forecasts calling for colder weather, particularly in the far northern Midwest, will give underlying support as it is "enough to put in the back of your mind that the threat is there."

DTN Meteorlogix said in a forecast that temperatures could fall into the low-to-middle 30s in parts of the Dakotas and west-central Minnesota, but that otherwise there are no significant frost or freeze concerns for the next 10 days.

"However, cool and wet conditions this week may be unfavorable for maturing crops and harvests...especially in the western Midwest region," the forecast said.

On the demand side, export sales have softened recently and will have to pick up as the harvest season progresses, McCambridge said.

The next upside price objective is to push December prices above solid technical resistance at the September high of $3.47 3/4 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 $3.38 and then at Friday's high of $3.40 3/4. First support is seen at $3.30 and then at Friday's low of $3.28 3/4.

Traders in the managed money category added to their net long position in CBOT corn for the week ended Sept. 22, the Commodity Futures Trading Commission said Friday.

Managed money added 4,737 contracts to their long positions and only 47 to their short positions, and were net long 70,145 contracts, according to the disaggregated commitments of traders report. Meanwhile, the supplemental commitment of traders report showed that traditional speculative funds remained slightly net short, with 147,125 long positions and 150,493 short positions.

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