The naira closed unchanged at 199 naira to the dollar, while it traded at 224 naira against the greenback at the parallel market, operated by bureau de change agents.
The central bank scrapped its bi-weekly forex auctions last month and fixed its clearing rate at 198 naira to the dollar, in a move to curb speculation on the currency. The naira has since been trading at around 197 to 199 to the dollar.
A total of 104.5 million dollar sales were carried out on Monday at a range of 197 to 199 naira to the dollar, just before the market closed, Thomson Reuters data showed, with dealers attributing some of the trades to a central bank forex sale.
The local units of Chevron sold $30.4 million while Shell sold an undisclosed amount to some lenders to buy naira for local use on Monday.
The central bank this month fixed the rate at which banks can buy dollars from oil companies at not more than 2 naira spread to its clearing rate, its latest attempt to prop up the currency hit by the drop in oil prices.