CHICAGO, Jan 29 (Reuters) - U.S. soybean futures fell to two-year lows below $12 a bushel on Monday, pressured by improving prospects for large South American harvests and worries about demand as top global soy buyer China struggles with a real estate crisis, analysts said.

Corn futures hit their lowest in more than a week and wheat notched a one-week low as declines in crude oil and a stronger U.S. dollar added to bearish sentiment in grains.

As of 12:33 p.m. CST (1833 GMT), Chicago Board of Trade (CBOT) March soybeans were down 16 cents at $11.93-1/4 per bushel after dipping to $11.91-1/2, the lowest on a continuous chart of the most-active contract since November 2021.

CBOT March corn was down 6-1/4 cents at $4.40 a bushel and March wheat was down 7 cents at $5.93-1/4 a bushel.

Soybean futures sagged as traders focused on rising expectations for large crops in Argentina and Brazil despite periods of stressful weather in both countries.

"Fear about weather in South America has gone, which in turn leads to worry about lack of demand for U.S. soybeans and corn. Should soybean demand from China return in the near future, this is likely to be met with Brazilian supplies," said Matt Ammermann, StoneX commodity risk manager.

Chinese demand for commodities seemed less certain, analysts said, as a real estate crisis deepened with a Hong Kong court ordering the liquidation of property giant China Evergrande Group.

"With the China economic news, there is still a worry about their economy over there. That is part of the problem today," said Sherman Newlin, an Illinois farmer and analyst with Risk Management Commodities.

Soy product futures were mixed. As soybeans declined, March soybean oil futures fell more than 3% while March soymeal bounced about 1% after setting a life-of-contract low.

Russian wheat export prices continued to decline last week amid oversupply pressure in the Black Sea region, but export volumes have gone up, analysts said. (Reporting by Julie Ingwersen; Additional reporting by Michael Hogan in Hamburg and Peter Hobson in Canberra; Editing by Ros Russell)