GRAINS-Wheat falls further to three-week low, corn and soybeans also down

PARIS/JAKARTA, Sept 4 (Reuters) - Chicago wheat fell for a third session on Thursday to touch a three-week low as ample global supplies continued to weigh on the cereal market.

Corn eased further from a six-week high, as a looming record U.S. harvest countered support from brisk exports, while soybeans extended losses to a three-week low as concern over a lack of Chinese demand hung over the oilseed market.

The most-active wheat contract Wv1 on the Chicago Board of Trade was down 1.2% at $5.16 a bushel at 1118 GMT, after touching its weakest level since August 14 at $5.15-1/4.

A large Russian export is set to boost wheat exports from the Black Sea region, while Australia's upcoming harvest is increasingly expected to be well above average.

In the European Union, Germany's winter wheat harvest is expected to rise 26% this year, the German agriculture ministry said on Wednesday.

"The market has come under pressure as a result of supplies. Grain production in general around the world has produced a decent crop, with very few material supply issues around the world," said Andrew Whitelaw, co-founder at agricultural consultants Episode 3 in Canberra.

Rain was also improving prospects for Northern Hemisphere wheat planting after summer drought. Precipitation in Ukraine's central, southern and eastern regions in late August has created satisfactory conditions for the start of winter crop sowing, agricultural meteorologists said on Thursday.

A pullback in corn prices after Thursday's six-week peak has added to pressure on wheat.

Forecasts by Allendale supported expectations for bumper U.S. corn and soybean crops this autumn, though the brokerage's production estimates were below those issued by the U.S. Department of Agriculture in mid-August.

Spot basis bids for soybeans and corn were steady to mixed at processing plants and grain elevators in the U.S. Midwest on Wednesday, as grain buyers prepare for harvest and farmers look to clear out their grain bins.

CBOT corn Cv1 was down 0.2% at $4.17-1/4 a bushel, moving back from Thursday's high of $4.24-1/4.

CBOT soybeans Sv1 slipped by 0.4% to $10.27 a bushel after reaching its lowest since August 12 at $10.26.

A lack of new-crop U.S. soybean purchases by China, amid trade tensions between Beijing and Washington, is clouding the demand outlook.

Beijing hosted non-Western leaders this week, dampening market hopes for a swift resolution to the trade conflict.