The apex bank is struggling to prop up the naira, which has taken a beating over the past few months as falling oil prices shook confidence in the assets of Africa's leading energy producer. Oil hit a five-year low on Monday.
The naira eased 1.1 percent on Monday, below the central bank's new target since an 8 percent devaluation two weeks ago to save declining foreign reserves, despite the bank selling dollars onto the market.
The balance that lenders hold with the central bank closed at a debit of 20 billion naira on Monday, compared with 45 billion naira on Friday. The banking system was about 400 billion naira in credit two weeks ago.
The bank also raised interest rates by 100 basis points to 13 percent, the first change in more than two years, and it debited 568 billion naira from the banking system.
