U.S. soybean futures ended lower on Wednesday in a profit-taking setback, retreating from more-than-two-year highs, while a weaker dollar and persistent supply worries continued to underpin prices and helped lift corn and wheat.

The losses in Chicago Board of Trade soybean futures marked the first time in eight sessions that the market lost ground. Soybeans have been rallying on concerns over hot and dry weather in major exporter Argentina. Corn futures also are garnering fundamental support from the detrimental crop weather there.

Both corn and wheat futures were lower early on profit-taking, but turned around by midday as the dollar weakened against both the yen and the euro. A cheaper dollar makes U.S. commodities more competitive internationally.

CBOT January soybeans ended down 9-3/4 cents, or 0.7 percent, at $13.66 a bushel, after sliding as low as $13.63-1/2. Funds sold a net of 4,500 soybean contracts.

March corn closed up 3/4 cent, or 0.1 percent, at $6.24 a bushel, the 10th straight session for a higher close. March corn put in an early low of $6.19, and then climbed to a new contract high of $6.26-1/2 and posted its highest intraday level for 2010. Funds bought a net 3,000 contracts.

March wheat settled up 1 cent at $7.99-1/4 a bushel, after sliding to $7.82-1/4 early. Funds bought a net 3,000 CBOT wheat contracts.

“The grain markets seem to be in a little bit of a profit-taking mode,” said North America Risk Management Services analyst Jerry Gidel. “We have made quite a run in the short term.”

Gidel and other analysts said they still expected prices to move higher going into the new year, with soybeans seen topping $14 and possibly $15 for the spot contract. But technical overbought signals and light profit-taking had been expected following the recent rally.

“The underlying factor fueling the rally is just the tightness of the balance sheet,” said Dan Cekander, a grain market analyst at brokerage Newedge USA. “I doubt that we’ve traded all of that tightness yet.”

Soybean and corn futures have been trading at their highest levels in more than two years on concerns over dry weather curbing supplies from Argentina, the world’s leading exporter of corn and soybeans.

Those supply-side concerns remained key supportive factors for corn and soybean markets as hot and dry weather linked to the La Nina weather phenomenon continued to threaten to curb corn and soy production in Argentina.

Some Argentine corn fields were drying up as they enter a key growth stage. A few light showers were forecast for the weekend, but temperatures were expected to remain above normal.

Private U.S. crop analyst Michael Cordonnier lowered his forecast for Argentina’s 2010/11 soybean production to 48 million tonnes.

Wheat markets continued to gain support from poor growing conditions in Australia, though wheat growers there had some relief in sight as good weather ahead could quicken the pace of the delayed harvest.

Crop analysis firm Australian Crop Forecasters estimated the harvest was 75 percent completed and should total about 24.4 million tonnes, with 10 million tonnes of lower grades.

Support was also seen from fresh export dealings. Egypt state buyer General Authority for Supply Commodities bought 60,000 tonnes of U.S. wheat, along with 120,000 tonnes from Argentina, on Tuesday, and Iraq and Turkey also tendered.

Wheat worries in the western U.S. Plains also offered support to wheat prices as parts of the growing area remained under drought stress with poorly developed new wheat stands.

Talk that funds are positioning to push more money into commodities next year was also bullish for the grain markets.