Brazil's central bank will continue intervening in the foreign exchange market using all tools at its disposal and in whatever size necessary to ensure the market functions smoothly, monetary policy director Bruno Serra said on Monday.

Speaking at an event at Bloomberg News in Sao Paulo as the central bank intervened in the spot currency market for the first time since November, Serra said Brazil's net FX reserves are robust enough to protect against external shocks.

Serra said the decision to triple the size of Monday's spot market dollar auction to $3 billion from the $1 billion announced on Friday shows the central bank's determination to do whatever it takes to calm extremely jittery markets.

"We will continue (intervening) as much as necessary as long as we believe that the market is not functioning smoothly," Serra said, noting how rapidly the situation has deteriorated.

"Interventions (so far) have been targeted, but can go on as long as necessary, until the foreign exchange market functions normally again," he said.

The central bank's $3 billion auction on Monday was its first spot currency market intervention since November. It followed a series of dollar swaps auctions in recent weeks that totaled almost $10 billion in nominal terms.

Monday's intervention helped lift the real off its fresh record low below 4.79 per dollar hit in early trading as local markets reacted to the intense volatility and steep declines across world markets triggered by a collapse in oil prices.

At mid-afternoon on Monday, the real was down around 1.5% from Friday, changing hands at 4.71 per dollar, while the Bovespa stock index was down 9%, meaning it was down around 25% from its peak at the end of January.

Serra insisted that Brazil has the policy tools at its disposal to tackle the current crisis, noting room to cut interest rates and lower reserve requirements on top of its FX instruments.