Union Bank said it raised N49.7 billion ($163 million) through a rights issued which it said was 120 percent subscribed.
The mid-sized lender launched the share sale last September at a ratio of five new shares for every seven held at N4.10 each.
Union Bank, set up 100-years ago, had said it planned to spend 80 percent of the funds to enhance its regulatory capital and boost working capital, Reuters reports.
“Having successfully raised the required capital, we will accelerate the pace of doing business in 2018 as we begin to deploy this fresh capital across identified business areas,” Chief Executive Officer Emeka Emuwa said in a statement.
The bank, in which Atlas Mara Ltd, the African investment vehicle of former Barclays boss Bob Diamond, owns a 22.1 percent stake, planned to raise funds to also tap opportunities lending to agribusinesses.
Union Bank was a former unit of Barclays Bank.
Shares in Union Bank, which have gained 42 percent last year, closed flat at 7.45 naira each on Monday.