Nigeria’s foreign exchange reserves fell to a 4-month low of $37.9 billion as of Nov. 7, down 3.99 per cent month-on-month after the central bank sold dollars to banks to prop up the value of the naira currency. Data published by the central bank on Tuesday showed the reserves were at $39.55 billion on Oct. 10. In July they stood at $37.89 billion. Nigeria’s central bank last week said it will continue to defend the local currency, which has fallen 6 percent so far this year on concerns about lower oil prices and an exit from the local debt and equity markets by offshore investors.