Argentina's currency, the peso, has fallen sharply on the currency markets after a one-week suspension of trading. It was the first day banks opened and the peso was allowed to float freely since the failure of the government's dual-exchange rate system of fixed international rates and floating domestic rates. Long lines formed at many banks, as Argentines fearing peso devaluation rushed to convert their cash into US dollars. Soon after the markets opened, it took up to 2.5 pesos to buy $1, compared with the $2.05 a week ago before the suspension of the market, reports said.