LONDON, May 10 (Reuters) - Chicago wheat futures rose to a nine-month high on Friday, buoyed by frost damage to crops in top exporter Russia, while corn and soybean prices also edged higher.

Russian wheat regions hit by frosts this month will re-sow crops that were killed by the cold, state news agency TASS quoted the agriculture ministry as saying on Thursday.

"This means that considerable frost damage is likely to occur," Commerzbank said in a note, adding the general weather situation for wheat, corn and soybeans remained challenging.

The most-active wheat contract on the Chicago Board of Trade was up 2.3% at $6.52-1/4 a bushel as of 0939 GMT, after climbing to a nine-month peak of $6.60.

Dealers said there were also concerns about wheat crops in the European Union.

Some 64% of French soft wheat was rated as in good or excellent condition by May 6, down from 94% a year ago, farm office FranceAgriMer said on Friday.

The rating was the lowest for the time of year since 2020.

Corn gained 0.7% to $4.59-1/2 a bushel, while soybeans rose 0.3% to $12.12 a bushel.

Soy and corn harvesting in Brazil's Rio Grande do Sul state has progressed slowly, according to estimates by crop agency Emater on Thursday, which confirm fears that floods continue to disrupt field work and will impose heavy losses on local farmers.

Devastating floods that hit Rio Grande do Sul should cause farmers to lose an estimated 1.32 million metric tons of soybeans, affecting overall output in the world's largest producer and exporter of the oilseed, consultancy AgResource said on Thursday.

Argentina's Buenos Aires grain exchange warned again on Thursday it may cut its forecast for the 2023/24 soybean crop, currently at 51 million metric tons, as warm weather and a lack of rain in the country's north have led to lower-than-expected yields.

Argentine grains ports and soybean crushing plants in the area surrounding the major Rosario hub are standing idle due to a nationwide strike launched on Thursday, the head of the major grains exporting nation's oilseed export chamber said. (Additional reporting by Mei Mei Chu in Beijing; Editing by Subhranshu Sahu, Varun H K and Jan Harvey)