US wheat futures fell to a one-week low on Thursday, turning lower after firming during the overnight session on technical selling, traders said.
Soyabeans and corn were firmer, supported by weakness in the dollar that investors hoped would spur export demand for US supplies. Soyabeans peaked at a 3-1/2 month high and briefly broke through the psychologically important $9 a bushel level.
The dollar drop sparked a rally across the commodities sector that spilled over into agricultural futures. Crude oil futures rallied to their highest since December 7.
But by mid-morning, corn, soyabeans and wheat had retreated from their highs, with traders saying that the ample global supply situation for all three commodities limited any potential rallies.
"We are looking at a situation where we are running into some overhead resistance," said Jim Gerlach, president of A/C trading. "It is nice to have the tailwind from the dollar ... but at some point you have got to have some of your own fundamental strength."
At 10:41 am CDT (1541 GMT), Chicago Board of Trade May soft red winter wheat futures were down 6-3/4 cents at $4.64 a bushel. CBOT May corn was just 1/4 cent higher at $3.68-1/2 a bushel and CBOT May soyabeans were up 3 cents at $8.97-1/2 a bushel.
The dollar's decline came after the Federal Reserve scaled down its own expectations of the number of US rate hikes this year on Wednesday afternoon.
On the demand side, weekly US export sales data on Thursday showed total corn and soyabean volumes above market expectations at 1.2 million tonnes, while wheat was within the range of estimates.