* Wheat futures fall as rain expected in Russia

* Corn slips on falling wheat prices and planting progress

* Soy falls on technical trading

(Updates throughout, updates prices, changes byline, changes dateline from PARIS to CHICAGO, adds bullets)

CHICAGO, May 30 (Reuters) - Chicago wheat futures turned lower for a second session on Thursday, falling from 10-month highs, as traders assessed whether forecasted rain in parts of Russia would halt a rapid decline in harvest estimates for the world's top exporter.

"The weather is giving the wheat market a reason to have a decent pullback," Chuck Shelby, president of Risk Management Commodities, said. "The market had a big run up, so it's not unusual to see those two factors cause a downward move."

The most-active wheat contract on the Chicago Board of Trade (CBOT) was down 18 cents at $6.75 a bushel as of 1540 GMT.

Corn futures dipped on pressure from the wheat market, as well as ripple effects from Tuesday's U.S. Department of Agriculture report showing speedy planting progress in the U.S. Midwest.

Soybeans were hovering in a fairly narrow range, amid signs of technical trading and ongoing concerns over Brazilian crop losses after devastating floods in the southern regions, brokers said.

Benchmark wheat prices surged to $7.20 per bushel on Tuesday, the highest since July, after the latest cuts to Russian harvest estimates due to dryness and spring frosts.

But weather charts suggest that rain in the week ahead should reach dry parts of Russia, while the start of harvesting in the southern U.S. Plains has also created seasonal supply pressure.

In the U.S. Midwest, brief windows of clear skies could help producers wrap up their planting, which have been delayed in some areas by spotty rains.

Meanwhile, Argentine farmers are speeding up badly delayed sales of soybeans, helped by higher global prices and better weather conditions for the ongoing harvest. But strong global supplies are expected to cap soybean futures prices for now, traders said.

CBOT soybeans were down 3-1/4 cents at $12.10-1/4 a bushel and corn was 5-3/4 cents lower at $4.49-3/4 a bushel. (Reporting by Heather Schlitz in Chicago. Additional reporting by Gus Trompiz in Paris and Peter Hobson in Canberra; Editing by Rashmi Aich and Mark Potter)