SINGAPORE, Jan 26 (Reuters) - Chicago wheat futures lost ground for the first time in three sessions on Wednesday, although tensions between key grain exporters Russia and Ukraine provided a floor under the market.

Soybeans and corn fell.

FUNDAMENTALS

* The most-active wheat contract on the Chicago Board of Trade (CBOT) fell 0.9% to $8.10-1/2 a bushel, as of 0127 GMT. Soybeans lost 0.7% to $13.97-1/2 a bushel and corn fell 0.7% to $6.15-3/4 a bushel.

* Tensions remained high after NATO said on Monday it was putting forces on standby and reinforcing eastern Europe with more ships and fighter jets in response to Russia's troop build-up near its border with Ukraine.

* Interruptions to grain flows from the Black Sea region could leave importers scrambling for alternatives such as European Union and U.S. wheat, and fuel food inflation.

* Ukraine is projected to be the world's third-largest exporter of corn in the 2021/22 season and fourth-largest exporter of wheat, according to International Grains Council data. Russia is the world's top wheat exporter.

* Smaller soybean crops expected in key South American producers are likely to push major soybean export business to the United States from June onwards, Hamburg-based oilseeds analysts Oil World said on Tuesday.

* However, Argentine rains in recent weeks have brought a "water bomb" to key farming areas in the northwest of Buenos Aires province, though there has been less water further to the south, the important Rosario grains exchange said in a report.

* China's use of wheat in animal rations in 2021/22 is expected to be less than half of the amount of last season, analysts and traders said, as elevated prices cut demand.

MARKET NEWS

* Wall Street ended the day lower on Tuesday after another tumultuous day of trading while oil jumped more than 2% as geopolitical tensions and Wednesday's Federal Reserve update occupied investor focus.

DATA/EVENTS (GMT) 1500 US New Home Sales-Units Dec 1900 US Federal Open Market Committee announces its decision on interest rates followed by statement (Reporting by Naveen Thukral; Editing by Rashmi Aich)