Venezuela's government and Central Bank today announced new rules for trading in bonds that have become an important way of getting foreign exchange, according to AP. Venezuelan banks will be able to sell investors' government bonds for dollars with prior approval by the Central Bank, which will have exclusive authority over the market. Many questions remain about the system, such as what band of trading prices will be permitted by the Central Bank and whether there are enough bonds available to meet demand for dollars. The government ordered a halt to bond trading three weeks ago as it moved to stem the falling value of the Venezuelan bolivar on the bond market. President Hugo Chavez's government maintains strict currency controls and sets official exchange rates. But the bond market had been a legal route for trading currency _ and a crucial source of hard currency for businesses that could not get dollars at the low official rates. Before the government intervened, the bolivar's value had fallen to about half the official rate of 4.30 to the dollar for nonessential goods.