*

Dry weather in key supplier Argentina supports soybeans

*

Rising COVID-19 cases in China seen curbing demand

SINGAPORE, Dec 29 (Reuters) - Chicago soybean futures were largely unchanged on Thursday, with the market holding on to last three sessions of gains as dry weather in Argentina underpinned prices.

Wheat fell after closing around 1.5% higher on Wednesday on support from cold weather across North America which is threatening the winter crop.

"Argentina's bottom line remains one of concern over poorly distributed rainfall," said one agricultural analyst.

"The rain expected this weekend into Monday will be extremely important and producers may advance with planting to take advantage of the moisture boost, while noting the lateness of the planting season. Opportunities to plant crops will begin to run out in the middle part of January."

The most-active soybean contract on the Chicago Board of Trade (CBOT) unmoved at $15.14-1/4 a bushel, as of 0331 GMT, wheat gave up 0.1% to $7.84-3/4 a bushel and corn fell 0.4% to $6.80 a bushel.

Soybean futures continue to find support from South American weather with a lack of rainfall in key growing areas of Argentina threatening the crop.

The dismantling of health restrictions in China has extended to food imports, as checks have been lifted on imported chilled and frozen foods, beginning Jan. 8.

However, there is caution in global markets about the short-term impact of China's COVID policy shift, with a surge in infections straining hospitals and prompting some countries to consider new rules for Chinese visitors.

Wheat has rallied in recent sessions as extreme cold weather gripped the United States, threatening to hurt winter wheat crops already weakened by drought.

Argentina's farmers have sold 78.9% of the 2021/2022 soybean harvest so far, the agriculture ministry said on Wednesday, as producers continue to benefit from a preferential exchange rate aimed at attracting sorely needed U.S. dollars.

Wheat prices faced pressure as Russia-focused agriculture consultancy Sovecon raised its forecast for Russia's 2022/23 wheat crop estimate to 101.2 million tonnes, up from the previous estimate of 100.9 million tonnes.

Commodity funds were net buyers of CBOT soybean, soymeal, corn and wheat futures contracts on Wednesday and net sellers of CBOT soyoil contracts, traders said. (Reporting by Naveen Thukral)