MOSCOW, May 8 (Reuters) - The Russian rouble weakened

against the U.S. dollar on Wednesday. By 0715 GMT, the rouble

was 0.57% lower at 91.63 to the dollar after

trading in a range of 91.158 to 91.780.

Against the euro, the rouble rose 0.05%

to 98.78, while it was down 0.1% to 12.61 against the yuan

.

Brent crude oil, a global benchmark for Russia's

main export, fell 1.0% to $82.30 a barrel.

Russian stock indexes were mixed. The dollar-denominated RTS

index fell 0.47% to 1,179.48. The rouble-based MOEX

Russian index gained 0.09% to 3,430.47.

($1 = 91.6275 roubles)

(Reporting by Reuters)