MOSCOW, Dec 13 (Reuters) - The Russian rouble

strengthened against the U.S. dollar but weakened against

China's yuan on Friday amid volatility caused by uneven sales of

foreign currency by exporting companies in the aftermath of new

U.S. sanctions.

By 0900 GMT, the rouble was up 1.4% at 103.50 against

the dollar, according to over-the-counter market data from

banks. The rouble had weakened by 1.7% to 14.04 against the yuan

in trading on the Moscow Stock Exchange.

The Russian currency was on track to finish the week lower

after rebounding last week. The rouble lost up to 15% against

the dollar after the U.S. sanctions were imposed on Nov. 22, but

it then recovered much of those losses.

The sanctions hit Gazprombank, Russia's third largest

lender, which handles payments for energy trade with Europe,

disrupting foreign trade transactions and the supply of foreign

currency to the Russian market.

The volatility in the rouble's exchange rate suggested that

Russian firms were still adjusting to the foreign trade

disruptions.

One-day rouble/dollar futures, which trade on the Moscow

Stock Exchange and are a guide for the over-the-counter exchange

rate, were up 0.5% at 103.75. The Russian central bank set an

official exchange rate at 103.27 to the dollar.