The spokesman did not put a figure on the size of the compensation but said the problems affected three percent of the 200,000 customers using the platform.

Aviva said last month it would pay 14 million pounds to compensate investors in its preference shares who sold the shares before the company reversed a plan to cancel them below market value.

The Financial Conduct Authority is reviewing Aviva's treatment of its preference share customers, a process which could lead to a formal investigation.

(Reporting by Carolyn Cohn; editing by Simon Jessop)