* Ample wheat supplies from Northern Hemisphere harvests weigh

* CBOT soybean futures hit lowest since 2020 again, corn down

*

HAMBURG, July 15 (Reuters) - Chicago wheat prices touched their lowest in about four months on Monday as pressure from freshly harvested crops in the United States and Russia weighed on prices.

Soybean prices extended last week's declines to reach their lowest since 2020 while corn also fell, with both pressured by good U.S. crop prospects.

The Chicago Board of Trade's most active wheat contract fell 2.7% to $5.35-1/2 a bushel by 1133 GMT after touching $5.34 a bushel for its lowest since March 18.

Soybeans slid 1.4% to $10.49-3/4 a bushel after hitting their lowest since November 2020 at $10.47-1/2 a bushel. Corn was down 1.2% at $4.09-3/4 a bushel.

Market attention was on large U.S. wheat, corn and soybean crops forecast by the U.S. Department of Agriculture (USDA) on Friday.

“Wheat, corn and soybeans are weakened by bearish sentiment following the USDA report on Friday and with U.S. weather forecast to be overall non-threatening to crops this week,” said Matt Ammermann, StoneX commodity risk manager.

“This could mean the USDA will give a positive picture of U.S. wheat harvest progress and U.S. crop conditions in its conditions report later on Monday.”

The USDA’s report on U.S. crop progress is scheduled later on Monday after the market close.

Meanwhile, low Russian wheat prices also depressed the market.

“Russian wheat continues to be offered in export markets at low prices," Ammermann said. "The U.S. has new crop wheat supplies and has to compete for export demand with Russian 12.5% protein wheat available cheaply at below $200 a ton FOB.” (Reporting by Michael Hogan in Hamburg Additional reporting by Naveen Thukral in Singapore Editing by Sherry Jacob-Phillips, Varun H K and David Goodman)