SAO PAULO Dec 3 Brazil's central bank sold all 20,000 currency swaps it offered in its second auction on Monday, strengthening the country's currency, the real, from around its weakest levels in over 3-1/2 years.
The currency swaps are derivatives that emulate the selling of dollars in the futures markets.
Earlier in the day, the bank had sold 21,800 swaps also maturing on Jan. 2, 2013, out of an offer of 40,000 contracts.
The real gained shortly after the auction was announced and was trading 1.45 percent stronger at 2.0994 reais per U.S. dollar. It slumped on Friday after weaker-than-expected economic growth data suggested the government would let the currency depreciate to prop up the economy.