SINGAPORE/PARIS: Chicago soybean prices extended gains on Friday while corn retreated slightly after a three-week surge on hopes for strong Chinese demand.

Wheat was on track for a fourth consecutive session of gains, mainly buoyed by technical elements.

The most-active soybeans contract on the Chicago Board Of Trade (CBOT) is up 4.5% this week, the biggest one-week percentage jump since September last year. It was trading 0.4% higher by 1042 GMT at 9.45-3/5 a bushel.

Corn was down 0.2% at $3.57-3/4 a bushel but gained 5% for the week and more than 11% over the past three weeks.

"The US Department of Agriculture (USDA) reported a hefty three quarters of a million tonne sale destined for China... that sale is an important validation of higher prices," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia.

Wheat was up 0.1% to $5.51-1/2 a bushel, bringing the weekly gain to 3%.

"From a technical point of view, the breach of the 200-day moving average in wheat was an incentive for the funds to increase their purchases," Agritel said.

Private exporters reported sales of 747,000 tonnes of corn to China and 140,000 tonnes of corn to unknown destinations, the USDA said on Thursday.

The agency said weekly export sales of wheat for shipment in the 2020/21 marketing year totalled 764,100 tonnes, topping forecasts that ranged from 400,000 tonnes to 700,000 tonnes.

The European Union cut its duty on maize (corn) imports to zero on Thursday to take account of a rise in US maize prices following a reduced forecast for the 2020/21 US maize harvest, the European Commission said.

The International Grains Council on Thursday raised its forecast for global corn production in the 2020/21 season by 2 million tonnes to a record 1.166 billion tonnes, reflecting an improved outlook for the US crop.

Meanwhile the European Commission cut its 2020/21 forecast for all cereals in the European Union's 27 countries.

Commodity funds were net buyers of CBOT soybean, corn, wheat, soyoil and soymeal futures contracts on Thursday, traders said.