SINGAPORE, Sept 27 (Reuters) - Chicago corn futures lost more ground on Monday with a rapidly advancing U.S. harvest season adding pressure on prices.

Wheat slid for the first time in four sessions while soybeans eased.

FUNDAMENTALS

* The most-active corn contract on the Chicago Board of Trade (CBOT) was down 0.4% at $5.24-1/2 a bushel, as of 0018 GMT, wheat lost 0.2% to $7.22-1/4 a bushel and soybeans gave up 0.2% to $12.83 a bushel.

* The market is focused on crop size and quality as the U.S. corn and soybean harvests are expected to ramp up across the U.S. Midwest.

* In the wheat market, a run of tenders by importers, harvest setbacks in the Northern Hemisphere and rumours about further Russian export restrictions supported futures last week.

* Prospects for a large wheat harvest in Australia have tempered global supply concerns, although China has made big advance purchases of the crop.

* Soymeal prices in China, the world's top consumer of the animal feed ingredient, are rising after at least 20 soybean crushing plants shuttered to comply with curbs on industrial power consumption, industry participants said on Friday.

* Five crushing plants in the northern city of Tianjin closed last week, Tianfeng Futures said in a note on Friday, including a facility owned by top trading house Louis Dreyfus Company.

* Ukraine has exported 12.8 million tonnes of grain so far in the 2021/22 July-June season versus 11.3 million at the same point a year earlier, agriculture ministry data showed on Friday.

* Large speculators raised their net long position in CBOT corn futures in the week ended Sept. 21, regulatory data released on Friday showed.

* The Commodity Futures Trading Commission's weekly commitments of traders report also showed that noncommercial traders, a category that includes hedge funds, increased their net short position in CBOT wheat and cut their net long position in soybeans.

MARKET NEWS

* Wall Street's S&P 500 posted a slim gain on Friday while major European markets slumped as investors weighed potential fallout from debt-laden China Evergrande and U.S. bond yields pushed higher after hawkish stances from central banks.

DATA/EVENTS (GMT) 1230 US Durable Goods Aug (Reporting by Naveen Thukral; Editing by Sherry Jacob-Phillips)