U.S. soybeans rose to a three-week high on Thursday, bolstered by strong soy product exports and forecasts for continued wet weather during the planting season in Argentina.
Wheat futures were lower for the first time in eight sessions and corn shed as much as one per cent, pressured by disappointing grain exports and by profit-taking following multi-week highs earlier this week.
U.S. export sales of soybeans, corn and wheat were the smallest in three weeks last week, with each missing trader expectations, U.S. Agriculture Department data showed on Thursday.
"Most of the crop markets reacted negatively to USDA's export sales report this morning," analyst Richard Brock of Milwaukee's Brock and Associates said in a note to clients.
However, only three months into the soybean marketing season, exporters have already sold 75 per cent of what USDA estimated for the entire year.
Export sales of U.S. soymeal last week were the highest in two months amid tight supplies in South America while exporters sold 100,000 tonnes of U.S. soyoil for the second straight week, the first time that has happened in two years.
There is little soymeal or soyoil available for export in South America and rains are expected to delay soy planting in Argentina, the No. 1 exporter of soymeal and soyoil.
"You have an underlying bullish force," said Jason Britt, president of brokerage Central State Commodities in Kansas City. "We are not slowing exports, even though today's numbers were a little lower."
Chicago Board of Trade (CBOT) January soybeans finished 1-3/4 cents higher at $14.48 per bushel in the third session of gains out of the last four trading days.
Soy futures for delivery in March and May -- when South American farmers will begin harvest their crops -- posted larger gains, with March's premium over January rising to the biggest in more than two weeks.
Investment funds bought 2,000 soybean contracts and sold 7,000 corn and 3,000 wheat contracts, sources on the Chicago trading floor said.
Wet weather is a mounting issue in Argentina while overall satisfactory crop weather continues in Brazil, said Andy Karst, meteorologist for World Weather Inc.
"It's still too wet in Argentina and there are a couple more rounds of rain coming over the next week, so there won't be a whole lot more planting going on," he said.
"It looks drier after the first week of December in Argentina, which will help, and Brazil looks good with frequent showers so there's not a whole lot of concern in Brazil for now," Karst said.
U.S. Plains stay dry
CBOT March wheat eased 5-3/4 cents to $8.85-1/2 per bushel, a decline of 0.7 per cent. CBOT March corn shed 5-1/4 cents to $7.58-3/4 per bushel, its first drop in four sessions.
Drought conditions in the U.S. hard red winter wheat belt had spurred the longest rally in wheat futures since July before prices eased as traders took profits on Thursday.
Still, dry weather in the U.S. Plains continues to cause concern about the newly seeded HRW wheat crop, Karst said.
"There is not a whole lot of rain or snow seen for either the Plains or the Midwest for the next week to 10 days. Maybe a light shower or two in the Midwest, but nothing significant," he said.
While the latest U.S. export sales of wheat and corn missed expectations, declining corn stocks in South America and less available wheat in the Black Sea region could turn more export business to the U.S. in the coming weeks.
"Corn and wheat sales will gradually increase throughout the month of December because we think the availability of supplies elsewhere will shrink," said Terry Reilly, senior commodity analyst at Futures International.
-- Michael Hirtzer covers the grain and livestock commodity markets in Chicago for Reuters. Additional reporting for Reuters by Sam Nelson and Karl Plume in Chicago.