Aviva Insurance has been fined almost 2.5 million euro for breaches of regulation.
The fines relate to Aviva Insurance and Aviva Life and Pensions, Ireland.
The Central Bank said the penalities imposed reflect the seriousness with which it views breaches of regulatory requirements which are designed to ensure that assets are properly managed and that life assurance policy holders are protected.
The Bank said both cases show evidence of serious inadequacies in Aviva's systems and control in relation to stock lending.
However Aviva co-operated in both instances and settled at an early stage.