CHICAGO (Dow Jones)--U.S. soybean futures are poised to start lower Thursday in a setback from strong gains Wednesday.

Traders and analysts predict soybeans for January delivery, the most-active contract, will start 6 to 8 cents a bushel weaker at the Chicago Board of Trade. In overnight electronic trading, the contract fell 7 cents, or 0.5%, to $12.76 a bushel.

Traders are expected to take profits on previous positions after futures rallied 3.2% Wednesday as weakness in the U.S. dollar and improving Chinese manufacturing data attracted buyers to commodities. Soybean futures pulled back overnight with corn and crude oil futures after rallying with the other markets Wednesday.

"Today's weakness is mostly a reaction to yesterday's sharp gains and ideas some sort of pause or correction is in order," said Duane Lowry, analyst for FarmAssist.com, an agricultural publication.

However, strong export demand could limit losses or potentially trigger a turnaround, analysts said. Total weekly U.S. soybean export sales, issued Thursday for the week ended Nov. 25, were 1.4 million tons, above estimates for 1 million to 1.3 million.

Soybean futures reached 26-month highs last month on worries strong demand from China, the world's largest soybean importer, was draining supplies. Prices have since pulled back about 5%.

Market participants also are concerned about dry weather in Argentina, the world's number three soybean exporter and leading exporter of soymeal and soyoil. Importers are hoping South America produces a big soy crop to help absorb strong global demand, particularly from China.

Forecasts look unfavorable for Argentine farmers, as heat this weekend and early next week will increase stress to crops, according to Telvent DTN, a private weather firm. The best chance for rain next week may be north of major growing areas in central Argentina, the firm said.

"If the South American weather concern storyline continues for much of December, we could exceed the November high and possibly by a notable amount," Lowry said. The high for a nearby contract in November was $13.37 3/4 a bushel.

In other news, soybean futures on China's Dalian Commodity Exchange settled sharply higher Thursday. Prices largely Wednesday's strong gains in U.S. futures, traders said.

-By Tom Polansek, Dow Jones Newswires; 312-341-5780; tom.polansek@dowjones.com