MOSCOW, June 25 (Reuters) - The Russian rouble

strengthened in volatile, low volume trade on Tuesday, with the

Russian market still jittery following new sanctions on Russia's

key financial systems that led to a halt in exchange trading in

dollars and euros in Moscow.

Sanctions on Moscow Exchange and its clearing

agent, the National Clearing Centre (NCC), have led to a range

of varying prices and spreads as trading shifted to the over-the

counter (OTC) market from June 14, obscuring access to reliable

pricing for the Russian currency.

On the interbank market, where liquidity can be low as major

Russian banks that have been sanctioned cannot participate, the

rouble traded 2% higher at 86.20 by 0817 GMT against the

dollar.

The average dollar-rouble mixed composite rate, calculated

by LSEG and based on data from international brokers and

counterparties, stood at 86.20, demonstrating that the

previously seen wide spreads - the difference between buying and

selling prices - were narrowing.

The central bank's official dollar-rouble rate was set at

87.37 for June 25, calculated on the basis of OTC trading.

The rouble strengthened sharply after the sanctions were

imposed amid low liquidity, caused by various technical

difficulties to do with interbank limits when closing FX deals

on the OTC market and as traders closed foreign currency

positions.

Against the yuan, the rouble was steady at 11.69, according

to an analysis of the OTC market. It had strengthened sharply

against the yuan in the previous session on news that the Bank

of China was stopping processing yuan payments involving

sanctioned Russian banks.

The yuan had surpassed the dollar to become the most traded

currency with the rouble in Moscow before the new sanctions were

imposed. It accounted for a 54% share of the FX market in May.

Ongoing issues with paying for imports, particularly with

China, are hindering a faster weakening of the rouble.

The rouble has eased from one-year highs reached in mid-June

since the government softened capital controls that have been

supporting the rouble since October. The volume of foreign

currency revenue that exporters must convert into roubles was

reduced to 60% from 80%.

Brent crude oil, a global benchmark for Russia's

main export, was unchanged at $85.98 a barrel.