The central bank will auction $230 million in forward contracts on the official market on Thursday after selling $370 million this week to boost dollar liquidity and help narrow the gap between the official and black market rates, traders said
The bank also sold $1.5 million on the spot market to help keep interbank rates at 305.50 per dollar. On the black market the naira firmed to 490 after opening at 505, traders said.

