The Brazil's real strengthened to end its first session of the year at 2.879 per dollar from Tuesday's 2003 close of 2.903.
Brazil's stock index rose in quiet trade on Friday following a firm open on Wall Street while investors sold dollars in a thin market to push the local currency to a stronger close, traders said.
Traders said investors had sold dollars they had bought earlier in the week to try to raise the Ptax, the exchange rate used when local dollar-denominated debt matures.
The market was, nevertheless, so thin that data showing Brazil's trade surplus almost doubled to $24.8 billion in 2003 from $13.1 billion in 2002 had not impacted the exchange rate.
"There's almost nobody working today, so I think that number should only be reflected on Monday when it should weaken the dollar," said Mario Battistel, director of foreign exchange at Novacao brokerage said earlier.
Meanwhile, the Sao Paulo Stock Exchange's benchmark Bovespa index, which gained a stunning 97 percent in 2003 to end the year at a record high, was 0.8 percent higher at 22,418.8 and on its way to yet another record high close.
Traders said, however, that the market was quiet and simply tracking early activity on Wall Street where many of Brazil's blue-chips have a dual listing.
Brazilian markets rallied strongly in 2003 after 10 percentage points in Central Bank interest rate cuts since June, and progress on fiscal and pension reform led investors to bet Latin America's biggest economy would rebound this year.
Brazil's Central Bank believes the economy will recover from near-zero growth in 2003 to expand 3.5 percent this year.