CHICAGO (Dow Jones)--Chicago Board of Trade corn futures are expected to open slightly weaker Tuesday following overnight losses amid outside pressure and prospects for better harvest progress.

Corn is called 1 to 2 cents lower. In overnight trade, December corn was down 1 cent to $3.77 a bushel and March corn was down 1 3/4 cents to $3.88 1/4.

After a strong recent rally above $4, the market retreated late Friday and into Monday, as outside markets softened and traders questioned whether fundamentals warranted such high prices.

Traders and analysts also say that forecasts for next week, while not completely dry, should be dry enough to allow farmers to harvest more of the crop.

The U.S. Department of Agriculture said in its weekly crop progress report Monday that 20% of the corn crop was harvested, up only 3 percentage points from last week's total of 17%. Last year's crop, which was considered late, was 37% harvested at the same point in the season, and the five-year average is 58%.

The harvest progress was at the low end of expectations, as analysts were expecting progress between 20% and 25%.

"It's certainly less than everyone was looking for," a trader said. "But if they get a few [dry] days, they'll be able to get a lot of work done."

As with the soybeans, key states remain far behind schedule. The crop in Illinois was only 14% harvested, compared to the average of 77%. Iowa's crop was 12% harvested, compared to the average of 49%.

An analyst said that as with most years, farmers will likely continue to harvest their soybeans ahead of their corn. But the potential for heavy winds in the Midwest later this week is a concern, he said, as they could knock down corn plants already weighted down by wet corn.

A firmer dollar and slightly weaker outside markets could keep a little pressure on corn Tuesday, a trader said.

Prices are still in a seven-week uptrend on the daily bar chart but now just barely, technical analyst Jim Wyckoff said.

"No serious chart damage occurred in corn Monday, but good follow-through selling pressure Tuesday would produce chart damage to begin to suggest that a near-term market top is in place," he said.

The next upside price objective is to push and close prices above solid technical resistance at last week's high of $4.13 1/2 a bushel.

The next downside price objective for the bears is to push and close prices below solid technical support at $3.68 1/2 a bushel, which is the last "reaction low" on the daily chart.

First resistance for December corn is seen at $3.85 and then at $3.90. First support is seen at Monday's low of $3.76 1/2 and then at $3.70.

In international news, India's corn production in the crop year that began Oct. 1 will likely fall 9% to 17.5 million metric tons following erratic monsoon rains in key growing regions, traders and analysts said Tuesday.

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