CHICAGO, Aug 7 (Reuters) -

Chicago Board of Trade soybean futures dropped 2.5% on Monday as rainy weather across much of the key U.S. crop belt and forecasts for good growing conditions for August pushed prices to their lowest in more than five weeks.

Wheat futures were nearly 3% higher as global supply concerns intensified, spurred by fears of an escalation of attacks on Black Sea shipping after a Ukrainian strike on a Russian tanker.

The good crop weather also pressured the corn market, which was on track for its ninth losing session out of the last 10, but losses were kept in check by the gains in wheat.

"The weekend rains were probably every bit as good as they were forecasting," said Mark Schultz, chief analyst at Minnesota-based Northstar Commodity.

At 10:33 a.m. CDT (1533 GMT), CBOT November soybean futures were down 37-1/4 cents at $12.96 a bushel. Prices bottomed out at $12.91, the lowest for the most-active contract since June 30.

CBOT September soft red winter wheat futures were 18 cents higher at $6.51 a bushel and CBOT December corn was down 3/4 cent at $4.96-1/2 a bushel.

"Wheat is being supported by increased risks from the Black Sea war with the Ukrainian attack on a Russian merchant ship over the weekend following the attack on Novorossiysk on Friday," said Matt Ammermann, StoneX commodity risk manager. "Concern is that the conflict could be moving to a new level."

Recent export deals for corn and soybeans added support to both commodities. Traders said the recent price declines have stirred up interest in U.S. supplies from overseas buyers.

Private exporters reported

the sale of 132,000 metric tons of soybeans to China and 251,460 metric tons of corn to Mexico for delivery in the 2023/24 marketing year, the U.S. Agriculture Department said on Monday morning. (Additional reporting by Michael Hogan in Hamburg and Enrico Dela Cruz in Manila; Editing by Sherry Jacob-Phillips, Mark Potter and David Gregorio)