THE Central Bank of Nigeria has introduced higher bills of 100, 200 and 500 for the naira as part of measures to restructure the currency, the bank said in a report on Tuesday. The CBN said President Olusegun Obasanjo has approved the new bills, which are expected to be in circulation between now and middle of next year. The bank said the bills would reduce the difficulties of carrying huge sums of money in smaller units. Until now, the 50 naira bill was the highest denomination in Nigeria. The CBN has taken a series of steps to shore up the value of the naira, which has fallen to around 104 to the dollar from 85 in January. Last week, the bank raised the liquidity ratio to 40% from 30%.