CHICAGO, Oct 19 (Reuters) - Chicago Board of Trade soft red winter wheat futures firmed on Monday, hitting almost six-year highs, on concerns about dry conditions across key global growing areas, traders said.

But gains were limited as investors stood by after prices have rallied 8.6% so far this month.

"The market is just kind of collecting its breath in this area and seeing what the next move will be," said Dan Basse, president of AgResource Co in Chicago.

Corn and soybean futures rose on bullish export expectations, shrugging off pressure from the ongoing U.S. harvest.

Chicago Board of Trade soft red winter wheat for December delivery settled 1-3/4 cents higher at $6.27 a bushel. The most active contract peaked at $6.36-3/4, its highest since Dec. 24, 2014, overnight.

Long-awaited rains arrived in parts of Russia over the weekend but more is needed, said consultancy IKAR.

CBOT December corn futures were up 3-1/4 cents at $4.05-1/4 and CBOT November soybeans were 4-1/4 cents higher at $10.54-1/4.

Brazilian farmers had sowed 7.9% of the estimated soy area through Oct. 15, the slowest pace in a decade as drought made planting riskier, consultancy AgRural said.

"Most areas are still dry, with planting about a third of the normal pace, and some of what was planted will need to be replanted," Arlan Suderman, chief commodities economist at StoneX, said in a note to clients. "That will delay the arrival of new-crop soybeans to the ports, extending the U.S. export season."

Private exporters reported sales of 345,000 tonnes of U.S. corn to unknown destinations and 123,000 tonnes of U.S. corn to Mexico, the U.S. Agriculture Department said on Monday.

Brazil's economy minister said over the weekend that the country would suspend tariffs on corn and soy imports from countries outside the Mercosur trade bloc until early next year. (Additional reporting by Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by Emelia Sithole-Matarise, Richard Chang and Sandra Maler)