Buenos Aires' stock index Merval lost strength on selective profit taking and fell 0.8 percent on the day, led by declines in shares of banks, but delivered a third straight week of gains. "The gradual increase in interest rates in the United States can be stopped at any moment," said Fernando Bergallo, director of FB Capital's currency board, noting the positive effect of the U.S. central bank statement. The central bank warned about negative effects on the economy and inflation if the crisis persisted.