* Liquidation ahead of Thursday's first notice day for deliveries
* March corn falls 1.7%
* Soybeans touch three-week low
CHICAGO, Nov 27 (Reuters) - Chicago grain and soybean futures tumbled on Monday after the Thanksgiving holiday weekend, pressured by slow demand and technical selling and as traders liquidated positions ahead of Thursday's first notice day for deliveries.
Chicago Board of Trade March and May corn futures and all wheat contracts fell to contract lows while soybeans declined to a three-week low.
"There's liquidation," said Dan Basse, president of AgResource Co in Chicago. "We pushed new lows in wheat and corn, sparking new selling and that is pretty much the story."
Chicago Board of Trade wheat fell 2.8% to $5.61 a bushel. Corn declined 1.7% to $4.55-1/2 a bushel after sinking to $4.53-3/4, the lowest for a most-active contract since December 2020. Soybeans fell 0.1% to $13.29-1/4 a bushel after earlier sliding to their lowest since Nov. 2.
"We're kind of stuck on a holiday affair here," said Dale Durchholz, a private commodity risk consultant in Bloomington, Illinois. "The volume and interest in trading has started to go down at this point so things can get a little bit sloppy simply because there is not a lot of volume and liquidity to offset it."
After trading settled, the U.S. Department of Agriculture reported 50% of winter wheat
received
good-to-excellent ratings, one point higher
than
expectations from agriculture analysts.
Soybeans found some support out of Brazil, where 2023/24 planting had reached 74% of the expected area as of Thursday, agribusiness consultancy AgRural said, making it the slowest progress in eight years as the country grapples with bad weather.
The market continues to closely monitor weather in the top exporter nation, where crop-threatening conditions remain in the forecast.
Some new demand for wheat was seen, with international tenders issued by Pakistan and Bangladesh. But cheap Black Sea wheat, especially from Russia, was tipped to win the business. (Additional reporting by Michael Hogan in Hamburg, Naveen Thukral; Editing by David Gregorio and Marguerita Choy)
