GRAINS-Soybeans stuck at six-week low on China demand uncertainty

CANBERRA/PARIS, Dec 10 (Reuters) - Chicago soybean futures fell for a fourth consecutive session on Wednesday to hold at a six-week low amid doubts that China will buy enough U.S. beans to prevent prices from losing ground in a well-supplied market.

Chicago wheat also eased for a fourth session, with increases to U.S. Department of Agriculture estimates for global production and stocks underscoring ample supply.

Corn ticked down after rising 1% on Tuesday when the USDA said U.S. exports would be larger than it had previously projected, leading to smaller U.S. ending stocks.

Prices faced additional pressure from Tuesday's announcement by Argentina, which said it would lower export taxes on crops including wheat, soybeans and corn, making them more competitive overseas.

Grains, like wider markets, were also awaiting direction from a U.S. Federal Reserve interest rate policy decision later on Wednesday, which could influence commodity prices via any movements in the dollar. MKTS/GLOB

The most-active soybean contract on the Chicago Board of Trade (CBOT) Sv1 was down 0.4% at $10.83-1/4 a bushel at 1216 GMT, after hitting another lowest since end-October.

Soybeans have fallen from a 17-month high of $11.69-1/2 in mid-November as optimism faded that China would quickly buy 12 million metric tons of U.S. soybeans under a trade truce with Washington.

The USDA has so far confirmed around 2.9 million metric tons of U.S. soybean sales to China. Despite the slow pace of Chinese purchases, the USDA left its U.S. export forecast unchanged on Tuesday. WASDE22

"The export target, maintained at 44.5 million tons, raises questions as the current pace makes it impossible to achieve," Argus Media analysts said, adding the USDA may have to lower the forecast in its January report.

Favourable weather is helping South American crops, with the USDA retaining its forecast for record 2025/26 soybean production in top grower Brazil.

CBOT wheat Wv1 was down 0.7% at $5.31 a bushel and CBOT corn Cv1 eased 0.2% to $4.47-1/4 a bushel.

Wheat supply looks ample, with only the threat of attacks on shipping in the Black Sea offering scope for price rises, said Dennis Voznesenski, an analyst at Commonwealth Bank.

"Production estimates have risen for 2025 crops in key export markets. Furthermore, production prospects are rising for 2026 in key import markets," he said.

Corn remained supported by the brisk export demand highlighted in the USDA report, as well as harvest setbacks in Ukraine, another major corn exporter, though large U.S. and South American supplies were keeping a lid on prices, traders said.