“Trading started at 9:00 am (0800 GMT) this morning. All the 24 commercial banks are participating. The offer is 249 to 265 naira to the dollar,” one forex trader told AFP.
At 1000 GMT, the naira was quoted at 262.50 against the dollar but the trader, who asked to remain anonymous, said supply and demand were still in the process of being matched.
“All the bids will be put on the table and the rate will based on the offers,” the trader said.
Analysts say the naira may settle in at around 250, compared with 350 to the greenback on the black market.
Nigeria had pegged the naira to the dollar at 197-199 since March 2015, even as other oil exporters have let their currencies devalue in the wake of plunging global crude prices.
President Muhammadu Buhari has previously said he would not “kill the naira” by letting it devalue.
But central bank governor Godwin Emefiele said last week the currency market would now be “purely market driven” as the country grapples with spiralling inflation, slowing growth, the weakening naira and foreign exchange shortages.