GRAINS-Soybeans stay weak amid biofuel doubts, corn and wheat drift

PARIS/BEIJING, Sept 18 (Reuters) - Chicago soybean futures fell for a second session on Thursday, pressured by weaker soyoil prices following a U.S. biofuel proposal that maintained uncertainty over exemptions to blending requirements.

Corn and wheat were little changed, consolidating near multi-week highs this week as investors assessed export demand and a U.S. interest rate cut. FRX/

The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 ended the overnight trading session down 0.2% at $10.41-1/4 per bushel, easing further from a two-week top during the previous session.

The market came under pressure after Tuesday's U.S. Environmental Protection Agency (EPA) proposal failed to clarify how biofuel blending obligations would be reallocated under the government's Small Refinery Exemption programme.

Biofuel mandates absorb a significant amount of soyoil for use in renewable diesel. CBOT soyoil BOv1 was down 0.3% after sliding nearly 3% on Wednesday.

"Uncertainty remains high regarding the EPA's upcoming decisions," Argus analysts said in a note.

A lack of Chinese purchases of U.S. soybeans, amid a trade battle between Beijing and Washington, was also hanging over the soy market as Midwest farmers enter their autumn harvest season.

The market is watching to see if a call scheduled for Friday between U.S. President Donald Trump and Chinese President Xi Jinping yields progress towards resuming soybean trade.

CBOT corn Cv1 edged down 0.2% to $4.26 a bushel. Prices had touched a 2-1/2-month peak on Wednesday linked to strong exports and doubts over the size of harvest yields.

CBOT wheat Wv1 was up 0.3% to $5.29-3/4 a bushel, after retreating on Wednesday from a seven-week high also supported by brisk exports.

Traders got an update on demand on Thursday from the U.S. Department of Agriculture's weekly export sales data. The volumes for corn, wheat and soybeans all came within a range of market estimates.