MOSCOW--The ruble firmed across the board in early trade on Monday as oil prices stabilized before major month-end tax payments in Russia.

The ruble gained 4% to 56.2 versus the dollar in the first minutes of trade on the Moscow exchange, heading away from its record low of 80.10 versus he dollar hit last week. Against the euro, the ruble strengthened more than 4% to 69.3 as prices for Brent crude rose above $60 a barrel.

The currency has become increasingly volatile since Russia's central bank let the ruble float last month, with the currency hitting fresh record lows on an almost daily basis until last week, as the price of oil, Russia's key export, plunged below $60 a barrel. The ruble selloff prompted authorities to step in with a combination of verbal and financial intervention.

The central bank data released Monday showed it sold $500 million from the country's international currency reserves to halt the ruble's rapid depreciation last Thursday. Since the beginning of the month the central bank has sold more than $10 billion in a bid to ease pressure on the ruble, which lost around 42% of its value versus the dollar so far this year.

This week the ruble is expected to get support from monthly tax payments, which usually prompt export-focused companies to convert dollars and euros into rubles to meet local liabilities. Last week President Vladimir Putin said he had personally contacted major companies to convince them to sell foreign currencies on the market.

Write to Andrey Ostroukh at andrey.ostroukh@wsj.com

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