MOSCOW, July 25 (Reuters) - The Russian rouble

strengthened against the dollar on Thursday, helped by rising

foreign currency sales by exporting companies and expectations

of a hefty interest rate hike by the central bank later this

week.

By 0730 GMT, the rouble was 0.7% higher at 85.65

against the dollar.

Russia's central bank is set to raise its key interest rate

by 200 basis points at a Friday board meeting, according to a

Reuters poll, as it struggles to contain inflation, fuelled by

state spending and lending growth.

Trading in major currencies shifted to the over-the-counter

market after Western sanctions on the Moscow Exchange

and its clearing agent, the National Clearing Centre, were

introduced on July 12.

Russian exporters started converting their foreign currency

earnings into roubles ahead of corporate tax payments due on

July 29. These sales are supporting the Russian currency.

Against the yuan, which had already become the most traded

foreign currency in Moscow before the latest sanctions were

imposed, the rouble firmed 0.6% to 11.75, according to an

analysis of the OTC market.

It was up 0.5% at 92.98 against the euro.

Brent crude oil, a global benchmark for Russia's

main export, was down 0.4% at $81.21 a barrel on concerns over

weak demand in China.