Members of the Finance and Leasing Association have pledged co-operation with the Financial Ombudsman Service (FOS) to handle complaints properly. Most relate to PPIs.

The FOS upheld an average of 59% of complaints against financial firms during the first half of 2009. It received almost 70,000 complaints, nearly 90% generated by customers of 142 of the 100,000 businesses the FOS covers.

The FOS deals with complaints when financial companies cannot resolve them. Its report says the top five high street banks – Lloyds, Barclays, RBS-NatWest, Abbey and HSBC – accounted for more than half the complaints. They all lend to retail car buyers.

Paul Harrison, FLA head of motor finance, said: “Our members are committed to responsible lending and comply with our self-regulatory lending code.

"This requires them to handle complaints quickly and sympathetically. There is also full co-operation with organisations such as the FOS.”

Harrison said many lenders also made donations to charities, including the Money Advice Trust, that provided information and advice on managing financial responsibilities.

He said motor finance members of the FLA supported its SAF (specialist automotive finance) initiative to voluntarily raise the standard of knowledge on finance in car showrooms for the benefit of customers.

The FOS named individual firms to force them to resolve more complaints themselves.

Walter Merricks, the outgoing chief ombudsman, said putting this information into the open would give businesses vital encouragement to improve.

“It should mean fewer of their customers having to bring complaints to the ombudsman that should already have been resolved,” he added.