MOSCOW, Nov 17 (Reuters) - The Russian rouble steadied near a more than four-month high against the dollar on Friday, supported by exporters' foreign currency purchases and high interest rates, but restrained from growth following a sharp drop in oil prices.

At 0710 GMT, the rouble was unchanged against the dollar at 89.18, not far from its strongest point since July 4 of 88.5725, hit on Thursday.

It had gained 0.5% to trade at 96.76 versus the euro and shed 0.1% against the yuan to 12.29 .

The pace of rouble appreciation and trading turnover on the FX market fell on Thursday, said Alor Broker's Alexei Antonov, suggesting that the rouble could weaken back towards 90 to the dollar should negative factors emerge.

"However, from the middle of next week, the supply of dollars and yuan may significantly grow due to the approaching peak of the tax period," Antonov said in a note.

Month-end tax payments usually see exporters ramp up FX sales to meet local liabilities.

The Russian currency has been buoyed by a presidential decree requiring some exporters to convert a significant portion of FX revenue, strengthening from beyond 100 to the dollar since the decree was announced last month.

The Bank of Russia hiked rates to 15% in late October and has signalled that another increase may be needed before it can start lowering the cost of borrowing.

Russia's wartime economy and the rouble's weakening have fanned high inflation this year, forcing millions of Russian families to cut back on spending.

Brent crude oil, a global benchmark for Russia's main export, was steady at $77.41 a barrel, having slumped to an over four-month low in the previous session.

"The deterioration of the situation in oil prices will have an impact," said Banki.ru Chief Analyst Bogdan Zvarich. "This factor, as a minimum, will restrain the rouble's further strengthening."

Russian stock indexes were lower.

The dollar-denominated RTS index was down 0.6% to 1.122.1 points. The rouble-based MOEX Russian index was 0.4% lower at 3,175.7 points.

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For Russian treasury bonds see (Reporting by Reuters; Writing by Alexander Marrow; Editing by Kim Coghill)