PARIS/SINGAPORE- Chicago soybeans drifted lower on Thursday after an eight-month high in the previous session as traders continued to assess South American harvest prospects after recent drought.

Progress in soy harvesting in Brazil and an easing in Malaysian palm oil futures after record highs before the Lunar New Year holiday encouraged soybean prices to consolidate. 

Corn fell for a second day, pressured by a rise in U.S. ethanol stocks and chart resistance after a seven-month high at the start of the week.

Wheat also extended a fall from Wednesday, with a firmer dollar underscoring doubts about U.S. exports as a standoff between Russia and the West over Ukraine was not affecting grain shipments through the Black Sea. 

Grain markets were awaiting weekly U.S. export data on Thursday for an update on demand.

The most-active soybean contract was down 0.8% at $15.32-1/2 a bushel, by 1059 GMT, after touching its highest since June on Wednesday at $15.64.

Soybeans have been the most active crop market in recent days as downward revisions to crop estimates in South America have spurred traders and analysts to raise demand projections for U.S. supplies for later this year. 

Record prices for palm oil, which competes with soyoil, have also supported oilseed markets due to supply concerns.

"With this inflammatory cocktail we could see soybeans continue to climb, but an improvement in crop conditions and prospects in South America could mean the contrary," said Cedric Renault, commodities desk head at Caceis in France.

CBOT corn was 1.0% lower at $6.16-1/4 a bushel while CBOT wheat  was down 1.2% at $7.46-1/4 a bushel.

Despite tensions over Ukraine, grain flows through the Black Sea have been uninterrupted, with Ukraine exporting 38.6 million tonnes of grain so far in the 2021/22 July-June season, up 31.6% from the same stage a season earlier. 

(Reporting by Gus Trompiz in Paris and Gavin Maguire in Singapore; Editing by Shailesh Kuber, Sherry Jacob-Phillips and David Evans) ((gus.trompiz@thomsonreuters.com; +33 1 49 49 52 18; Reuters Messaging: gus.trompiz.thomsonreuters.com@reuters.net))