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.

At 11:20 a.m. CDT (1620 GMT), Chicago Board of Trade soft red winter wheat for December delivery was up 2-3/4 cents at $6.28 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 cents higher at $10.54.

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.

"Any reduction in Brazil's crop will help push more export demand to the United States, where soybean supplies are already looking tighter," said Matt Ammermann, StoneX commodity risk manager.

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 for delivery in the 2020/21 marketing year, 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 and Richard Chang)