* Large global wheat production expected

* Corn firm as U.S. crop prospects assessed

* Soybeans rise on strong demand for U.S. biofuel

HAMBURG, Aug 3 (Reuters) - U.S. wheat futures fell by more than 1% on Monday as increasing signs of abundant global supply and slack demand weighed on prices while corn and soybeans rose.

The Chicago Board of Trade's most active wheat contract fell 1.2% to $5.24-1/2 a bushel by 1101 GMT.

Corn was up 0.1% at $3.27-1/2 a bushel and soybeans gained 0.5% to $8.97-1/2 a bushel.

Improved harvest outlooks in major wheat-producing regions was driving losses.

“Wheat is suffering from an increasingly good supply picture while the COVID-19 crisis continues to cause demand destruction,” said Matt Ammermann, commodity risk manager at StoneX.

Russian agriculture consultancy IKAR on Monday said it had raised its forecast for Russia's 2020 wheat crop to 79.5 million tonnes from 78 million tonnes.

"Increasing Russian production remains the focus to start the week. Harvest momentum might now push us back to 80 million tonnes," Ammermann said.

“Australian weather is also looking more positive, raising the prospects of more wheat exports from Australia after its virtual three-year absence from export markets.”

The Brazilian wheat crop could surpass 7 million tonnes this year and reach a record high, possibly cutting the country's import demand.

“Corn is being torn between rising expectations of high U.S. crop yields against the impact of very large sales to China in the past week ... U.S. Midwest corn weather is also positive as we wait for the weekly U.S. crop conditions report later today," Ammermann said.

"Soybeans are supported by surprisingly firm demand for soyoil for U.S. biodiesel production as COVID-19 has caused demand destruction in other sectors.”

The U.S. Energy Information Administration said volumes of soyoil used for biodiesel in May rose to 778 million pounds, up from 672 million pounds in April. (Reporting by Michael Hogan Additional reporting by Colin Packham Editing by David Goodman )