GRAINS-Soybeans flat, set for first weekly loss in 7 on U.S. harvest pressure

* Soybeans down 4.1% this week, biggest weekly drop in six months

* U.S. harvest to boost world soybean supplies; wheat down 5% this week (Adds quote in paragraph 3, details on Argentina wheat weather, IGC corn forecast)

SINGAPORE, Sept 25 (Reuters) - Chicago soybean futures were little changed on Friday, with the market set for a weekly loss after rallying for the last six weeks, as rapidly advancing U.S. harvest added pressure on prices.

Wheat is poised to end the week with a decline of nearly 5%, after closing higher last week.

“U.S. harvest is progressing well,” said one Singapore-based trader at an international trading company. “I wouldn’t say yields are fantastic but they are pretty decent.”

The most-active soybean contract on the Chicago Board Of Trade slid 4.1% this week, on track for the biggest weekly loss since mid-March.

Soybeans were unmoved at $10.00 a bushel, as of 0318 GMT, after closing 1.4% lower on Thursday.

Wheat is down nearly 5% so far this week, on track for its biggest weekly loss since Aug. 7, while corn has lost more than 3%, after gaining ground for the last two weeks.

Strong demand led by top importer has driven a rally in soybean prices for the last six weeks.

A U.S. Department of Agriculture (USDA) report showed export sales of corn at 2.139 million tonnes and soybeans at 3.195 million tonnes, both topping the higher end of market expectations.

However, the USDA did not report a fresh deal for soybeans to China in its daily reporting system, snapping a stretch of 14 straight trading days after a so-called flash sale has been announced.

Drought-hit Argentine wheat fields might get some relief over the weekend if rain forecasts prove correct, the Buenos Aires Grains Exchange said in its weekly crop report on Thursday. Some 60% of planted area was in average to very dry condition, it added, up from 50% a week earlier.

The International Grains Council on Thursday trimmed its forecast for global corn production in the 2020/21 season, partly reflecting a reduced outlook for the U.S. crop.

Commodity funds were net sellers of CBOT corn, soybeans, soymeal and soyoil futures contracts on Thursday, traders said. The funds were net buyers of wheat futures contracts. (Reporting by Naveen Thukral; Editing by Rashmi Aich)