The Irish-based division of world banking giant Citigroup has been fined 550,000 euro for breaching reporting rules on cash flows.
The Citibank Europe wing of the company was found to have contravened liquidity regulations five times between January 2009 and July 2012.
The Central Bank of Ireland said the breaches related to issues around the analysis and reporting of cash flows but that the bank's liquidity position never fell below required levels.
Citibank Europe identified the problem itself.
"Citibank Europe plc self-identified the regulatory liquidity reporting errors in 2012 and immediately notified the matter to the Central Bank of Ireland," it said.
"We regret the reporting errors occurred. At no time did Citibank Europe plc breach any liquidity limits and at all times the bank was highly liquid with strong capital ratios. We are pleased that this matter is now resolved."