MOSCOW, May 21 (Reuters) - The Russian rouble

strengthened to a near four-month high against the U.S. dollar

on Tuesday, approaching the 90 threshold on the support of high

interest rates, state foreign currency sales and capital

controls.

By 1508 GMT, the rouble was 0.8% higher at

90.07 to the dollar, its strongest point since Feb. 1.

Against the euro, the rouble rose 0.7%

to 97.93. It also gained 0.7% to 12.42 against the yuan

.

Capital controls introduced by presidential decree in

October 2023 require dozens of undisclosed exporting firms to

deposit a high percentage of foreign currency earnings with

Russian banks and then sell most of those proceeds on the

domestic market. The controls were extended by a year at the end

of April.

The state's overall forex sales were sharply

increased

to 6.3 billion roubles ($69.83 million) a day in May from

0.6 billion roubles a day in the previous month, further

buttressing the Russian currency.

After three successive interest rate holds at 16%, the

central bank has adopted a more hawkish stance ahead of its next

meeting on June 7, with inflation remaining stubbornly high.

Expectations for the start of the key rate cutting cycle

have shifted to 2025, though the chances of a moderate cut later

this year remain highly probable, Promsvyazbank analysts said on

Tuesday.

Brent crude oil, a global benchmark for Russia's

main export, fell 0.5% to $83.29 a barrel.

Russian stock indexes fell. The dollar-denominated RTS index

fell 0.2% to 1,185.0. The rouble-based MOEX Russian

index lost 0.9% to 3,463.9.

($1 = 90.2205 roubles)