MOSCOW, Jan 15 (Reuters) - The Russian rouble was flat

against the U.S. dollar and strengthened slightly against

China's yuan on Wednesday as net sales of foreign currency by

the central bank on the domestic market have increased.

The rouble was at 102.70 to the dollar at 0915 GMT,

unchanged from the previous day, over-the-counter market data

showed. The rouble strengthened 0.3% to 13.89 against the yuan

in trading on the Moscow Stock Exchange (MOEX).

The rouble has been weakening against the yuan, now the only

exchange-traded major foreign currency in Russia, following the

U.S. energy sanctions that targeted Russia's oil sales to China,

its major trading partner.

Under a complex scheme of market operations the central bank

buys and sells yuan, the only major foreign currency it can now

hold, increasing the net sales when necessary to ensure

sufficient supply of the currency on the market.

The net sales of the yuan have increased by almost one third

on Wednesday, providing support for the rouble and countering

the impact of the U.S. sanctions.

One-day rouble/dollar futures, which trade on MOEX and are a

guide for the over-the-counter exchange rate, were also flat at

103.65. The Russian central bank set the official exchange rate

at 103.44.