CHICAGO, Jan 11 (Reuters) - Chicago Board of Trade soybean futures regained some ground on Thursday but remained near their lowest level since December 2021 amid lackluster demand for U.S. exports and an improved South American supply outlook.

Corn futures eased and were close to their lowest since December 2020. Wheat also slumped at the CBOT.

Traders were adjusting positions while awaiting the release of quarterly U.S. Department of Agriculture (USDA) grain stocks data and a monthly agricultural supply/demand report on Friday. The data can set the tone for grain and oilseed markets through the first part of the year.

"We've been down in both corn and beans quite a bit coming into this report," said Ted Seifried, chief market strategist for the Zaner Group. "The market has kind of paused."

Most-active CBOT soybean futures were up 2 cents at $12.38-1/2 a bushel by 12:20 p.m. CST (1820 GMT) after slipping earlier to $12.34-1/4. On Tuesday, the market reached $12.34, the lowest in more than two years.

Corn was down 1-1/2 cents at $4.58 a bushel after falling to a three-year low of $4.51-3/4 on Tuesday. Wheat was down 6-3/4 cent at $6.04 a bushel at the CBOT.

Traders on Friday will review the USDA's estimates for South American soy and corn production, after hot, dry weather hurt crops in parts of Brazil.

The International Grains Council raised its forecast for global corn production on Friday.

Recent rains mean Brazil's soy harvest will also be better than previously feared, while Argentina's crop will also be sizeable, said Rabobank analyst Vitor Pistoia. U.S. soybean exports this season are well behind last year, with cheaper Brazilian beans dominating the world market.

The USDA on Thursday reported net export sales of U.S. 2023/24 soybeans in the week ended Jan. 4 were 280,500 metric tons, below trade estimates of 325,000 to 950,000 tons.

In a daily sales announcement, the USDA separately confirmed private sales of 175,000 metric tons of U.S. corn to Mexico. (Reporting by Tom Polansek in Chicago; additional reporting by Peter Hobson in Canberra and Sybille de La Hamaide in Paris; editing by Varun H K, Sohini Goswami, David Goodman and Jonathan Oatis)