SAO PAULO(Reuters) – Brazil’s central banks sold currency swaps worth $1 billion in a surprise auction Wednesday afternoon. The sale lifted the currency from near six-month-lows.

The central bank said it had sold all 20,000 foreign exchange swap contracts offered in a nonscheduled auction – double the volume offered in the bank’s last surprise auction on Sept. 30.

The real was affected immediately by the sale, and it traded at 0.5% higher at 5.51 Reals per dollar.

With investors scared by political risks and a fragile recovery, the real has fallen by just 3% against the U.S. dollars this year. There is also the possibility of rising interest rates for more prosperous countries.

Brazil’s central banking announced that it will hold two more weekly auctions of traditional currencies swaps to satisfy banks who want to sell their positions in derivatives markets.

Earlier on Wednesday, the central bank’s Political Economy Director Fabio Kanczuk said that there had been a smaller-than-expected market reaction to the bank’s announcement of those regular swap auctions.