Three of the biggest high street banks are underperforming in their relationship with small firms, a major report claimed today.

Barclays, Lloyds TSB and NatWest were bottom of a league table produced by the Forum of Private Business (FPB).

Its report, Private Businesses and their Banks, was compiled in conjunction with the University of Nottingham and is the largest and longest running report of its kind, surveying 5,000 small businesses about their relationship with their bank.

The report showed that although the performance of the banking industry had remained stable over the last two years, the major high street banks are being outshone by their smaller rivals.

Allied Irish Bank (AIB) tops the table for the sixth report running, a position it has now held for 10 years.

Factors taken into account, when compiling the league table, included competitiveness of interest rate and charges, knowledge of industry, efficiency and reliability.

Significantly, the report showed that more than 40% of small businesses banking with Barclays, Lloyds TSB and NatWest had cause to complain.

Bank performance table:

1. AIB 2. Yorkshire 3. Clydesdale 4. HSBC 5. RBS 6. Bank of Scotland 7. NatWest 8. Lloyds TSB 9. Barclays FPB's chief executive Nick Goulding said: "The report clearly shows a worrying variation in bank performance when dealing with small businesses."

He said there was little evidence in the report to suggest that the Office of Fair Trading recommendations, designed to make bank switching easier for businesses, had led to significant numbers of firms actually doing so.

"There has been serious variation between the major banks with regard to the OFT recommendations.

"There is confusion and lack of clarity with respect to bank charges and interest on current accounts. This suggests that businesses, banks and policy-makers must review and clarify the actual terms and conditions being provided."

Chris Bayliss, chief operating officer at Yorkshire Bank, said: "This is a very comprehensive survey and so we are obviously delighted to have again been rated so highly by our customers.

"It is a real testament to the enthusiasm, expertise and commitment shown by our staff in delivering high quality services and products to our customers.

"However, the survey also found that far too many businesses seem willing to settle for a poor deal on their banking, even though there are evidently much better providers - such as Yorkshire - around."

John Rendall, head of business banking at HSBC Bank, said: "We already know that more businesses rate our service as excellent than any other bank.

"The managers in our new commercial centres are committed to spending three days out of five on the road visiting businesses and senior managers will typically spend four years in the role."