UPDATE 1-Russian rouble soars to one-week high past 91 vs dollar

(Updates at 1023 GMT)

MOSCOW, Dec 11 (Reuters) - The Russian rouble strengthened on Monday, soaring past 91 against the dollar to a one-week high, supported by currency controls and high interest rates as the market gears up for Russia's final rate decision of the year this week.

The central bank is widely expected to raise borrowing costs again at its meeting on Dec. 15, by 100 basis points to 16%.

The market is also likely to pay close attention to a speech by President Vladimir Putin on Thursday. Putin, who last week said he would run again for election next year, faces numerous economic challenges, but the West's limited success in imposing an oil price cap is easing pressure for now.

By 1023 GMT the rouble had strengthened by 1.2% against the dollar to 90.80, its strongest since Dec. 4.

It had gained 0.7% to trade at 97.93 versus the euro and firmed 1.2% against the yuan to 12.63.

"The rouble is a bit surprising as it is not showing December's traditional weakness," said Alor Broker's Alexei Antonov. "The technical picture for the rouble has improved significantly."

The rouble has weakened for two weeks running after the end of the month-end tax period.

It had previously registered seven weeks of gains, rebounding from more than 100 to the dollar thanks to reduced capital outflows since Putin's October introduction of forced conversion of some foreign currency revenue by exporters.

Brent crude oil, a global benchmark for Russia's main export, was down 0.3% at $75.62 a barrel.

Russian stock indexes were mixed.

The dollar-denominated RTS index was up 0.8% at 1,062.6 points. The rouble-based MOEX Russian index was 0.5% down at 3,063.4 points.

(Reporting by Alexander Marrow Editing by David Goodman)