Nigeria’s currency weakened to a four-year low in the parallel market after the central bank’s efforts to coax banks to sell more dollars to customers failed to bridge the widening gap between the official and street rates. Unauthorized dealers were offering the naira at 502 per dollar on Wednesday from 500 last week according to abokifx.com, a website that collates the data. That’s the weakest since February 2017. The rate widens the spread between the official and the parallel market rate to 22%, when compared with the spot rate of 411.13 naira a dollar as of 1.55 p.m. in Lagos on Wednesday. Nigeria, Africa’s biggest economy, has devalued its currency thrice since March last year as lower oil income, which accounts for about 90% of dollar earnings put pressure on external reserves. Some people are switching their naira savings into dollars fearing further devaluation. Goldman Sachs Group Inc. forecasts […]