The rate of complaints made to the Financial Ombudsman Service against financial firms surged by 18% in the second half of 2009.

In all, FOS registered 82,136 complaints, during the period.

However, the number of complaints accepted by the FOS dipped to 53%.

"While the number of cases referred by consumers to the Ombudsman has continued to increase substantially, it's encouraging to see that some businesses are committed to handling complaints better", said the Interim Chief Ombudsman, David Thomas.

"However, there is evidently still room for significant improvement in the way other financial businesses handle complaints - judged by the proportion of cases where we overturn the decision that the businesses have themselves come to in their own earlier investigation of their customer complaints", he added.

Banking giants Abbey, Barclays, HSBC, Lloyds and RBS group accounted for nearly 47,000 of the new complaints received by the FOS.

On average, 68% of complaints about general insurance were supported, compared with 47% for banking and lending, 37% for mortgages and home finance, 44% for investment, and 33% for life insurance and pensions.

More than 90% of general insurance complaints against MBNA and the Co-op bank were found to be accepted.