PARIS/SINGAPORE: Chicago soybeans eased for a third session on Thursday as traders expected forecast rain to help crops in dry U.S. areas and they assessed results from a major Midwest field tour.
Corn futures slipped to a one-week low as rain was also expected to avert further stress to corn crops in parched western growing belts.
Wheat also fell, giving back some of its sharp gains this month linked concerns over northern hemisphere harvest prospects.
A rally in the dollar, which hit a nine-month peak against a basket of other major currencies, also weighed on Chicago grains as it did on other dollar-denominated commodity markets.
"Weather forecasters are expecting cooler and wetter conditions in the northwest of the Midwest starting this weekend," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.
"The rains are likely to arrest the yield declines."
While moisture is seen coming too late to improve significantly yield potential in soybeans and particularly corn, it could curb drought losses in western regions and so make less of a dent to strong harvest prospects in the eastern Midwest.
The market was digesting findings from this week's Pro Farmer Midwest Crop Tour.
Latest feedback from Wednesday projected corn yields and soybean pod counts in Illinois above a three-year average. In western Iowa, corn yields and soy pods were seen higher than last year, but below the three-year average for corn.
The most-active soybean contract on the Chicago Board of Trade (CBOT) was down 1.3% at $13.35-1/2 a bushel by 1057 GMT.
Soybeans have retreated from a two-week high on Tuesday that was supported by a run of exports, notably to China.
The USDA has announced export sales of U.S. soybeans each business day since Aug. 5 and the market will get a further update through weekly export data due at 1230 GMT.
Corn was down 1.2% at $5.58-1/4 a bushel, while wheat gave up 1.4% to $7.40-1/2 a bushel.
Chicago wheat soared to an 8-1/2 year high last week on lower than expected projections of supply in northern hemisphere exporting countries.
"Pressure from the dollar seems to be affecting Chicago while Black Sea wheat remains competitive despite an increase in prices," a European trader said.