SINGAPORE, April 17 (Reuters) - Chicago wheat prices lost ground on Monday with the market giving up some of last session's gains on pressure from plentiful global supplies and continued Black Sea shipments despite Russia's threats on the wartime export deal.

Corn slid as the market took a breather after Friday's rally, while soybeans inched higher.

FUNDAMENTALS

* The Chicago Board of Trade's (CBOT) most-active wheat contract fell 0.6% to $6.78-1/2 a bushel, as of 0039 GMT, corn lost 0.2% to $6.65 a bushel, and soybeans added 0.1% to $15.02 a bushel.

* The condition of French soft wheat improved slightly in the week to April 10, with 94% of crops rated to be in good or excellent condition compared with 93% the previous week, farm office FranceAgriMer said on Friday.

* Ongoing Ukrainian shipments through the U.S.-brokered grain corridor, despite inspection delays, and large Russian exports have tempered immediate worries about the Black Sea trade.

* A senior Russian diplomat said on Friday the West still has time to remove "obstacles" hindering the implementation of the Black Sea grain deal which allows safe wartime export of grain from several Ukrainian Black Sea ports.

* UN Secretary-General Antonio Guterres has written to Russia, Ukraine and Turkey to raise concerns about the implementation of the deal, a UN spokesman said on Friday.

* Last week, the corn market was underpinned by strong demand. The U.S. Department of Agriculture announced large corn export sales to China for a second straight day on Friday.

* For soybeans, Argentina's Buenos Aires grains exchange on Thursday said farmers would likely leave large tracts of fields unharvested due to damage from a historic drought.

* However, a record Brazilian soybean harvest has tempered concern about drought losses in Argentina.

* Large speculators trimmed their net short position in CBOT corn futures in the week to April 11, 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

* Asian stocks opened cautiously on Monday as U.S. earnings season gets into full swing, while a raft of Chinese data will offer insight into how the world's second-largest economy is recovering.

DATA/EVENTS (GMT) 1000 EU Reserve Assets Total March (Reporting by Naveen Thukral; editing by Uttaresh Venkateshwaran)