* Soybeans up for 3rd session as supplies tighten in top exporters

* Corn rises to near one-week high on strong demand, wheat firms

SINGAPORE, Nov 17 (Reuters) - Chicago soybean futures rose about 1% on Tuesday to their highest in more than four years as tightening supplies in key exporting countries and strong demand buoyed the market.

Corn rose to its highest in almost a week, while wheat gained more ground.

"U.S. soybean supply situation is very tight because of strong Chinese purchases and it might end up importing beans from Brazil early next year," said one Singapore-based trader. "Just as Brazil is buying U.S. beans."

Brazil and the United States are the world's biggest exporters of the oilseed, while China is the top importer.

The most-active soybean contract on the Chicago Board Of Trade (CBOT) was up 0.9% at $11.64-1/4 a bushel, as of 0325 GMT, after rising earlier in the day to its highest since June 2016 at $11.67 a bushel.

Corn was up 0.8% at $4.19-3/4 a bushel, having gained 1.4% in the previous session and wheat rose 0.5% to $6.01 a bushel, having closed up 0.8% on Monday.

The U.S. Department of Agriculture reported more than 2.2 million tonnes of soybeans inspected for export last week, about three quarters of it bound for China.

Nearly 815,000 tonnes of yellow corn were also inspected for export, including almost 280,000 tonnes destined for China.

The National Oilseed Processors Association on Monday reported the U.S. October soy crush at a record-high 185.245 million bushels, topping all trade estimates.

Better-than-expected rains in Argentina and parts of Brazil capped gains in corn and soybeans following early-season worries that dry conditions would limit crops.

Conditions for Russia's winter wheat sowings remain tense, especially in part of Volgograd, Stavropol and nearby regions, despite some improvement seen in recent weeks, analysts said on Monday.

Large speculators cut their net long position in CBOT corn futures in the week to Nov. 10, regulatory data released on Monday showed.

The Commodity Futures Trading Commission's weekly commitments of traders report also showed that non-commercial traders, a category that includes hedge funds, cut their net long position in CBOT wheat and raised their net long position in soybeans. (Reporting by Naveen Thukral, Editing by Sherry Jacob-Phillips)