HAMBURG  - Chicago wheat dropped for a third consecutive session on Monday as abundant world supplies weighed on prices.

Soybeans fell as good weather raised expectations of a big U.S. harvest while corn was supported by bargain buying after falling on Friday.

The Chicago Board of Trade's most active wheat contract fell 0.5% to $4.93 a bushel by 1047 GMT, soybeans were down 0.2% at $8.65-3/4 a bushel and corn was unchanged at $3.20-3/4 a bushel.

Estimates for a large Canadian wheat crop, rising forecasts for Russia's harvest, improving conditions in Australia and good early signs for the U.S. spring wheat harvest are weighing on wheat prices.

“Wheat remains under pressure from continued expectations of larger than expected global supplies while demand is suffering from the COVID-19 crisis,” said Matt Ammermann, StoneX commodity risk manager. “Harvest forecasts are being increased in Russia and Canada while Australia is expected to be back in the export markets again.”

“Overall favourable crop weather in the United States is weakening soybeans with rain in the Midwest over the weekend and some more expected, which all bodes well for the U.S. crop in the key development month of August.”

“Corn is little changed with U.S. weather overall positive.”

The monthly world supply and demand report from the U.S. Department of Agriculture (USDA) on Wednesday is expected to forecast plentiful supplies for all three commodities. Analysts also expect raised estimates for U.S. wheat, corn and soybean crops.

A big prospective U.S. corn crop looks more likely to be realised while demand is shaky, said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.

“Markets are positioning ahead of the USDA report of U.S crop conditions later on Monday and the world supply and demand report on Wednesday, with a positive picture of U.S. crop conditions expected,” Ammermann said.

(Reporting by Michael Hogan Additional reporting by Naveen Thukral Editing by David Goodman ) ((michael.j.hogan@thomsonreuters.com; +49 172 671 36 54; Reuters Messaging: michael.hogan.thomsonreuters.com@reuters.net))