Birmingham has been branded Britain's worst city for business crime with the cost burden for firms on the increase.

More than a quarter of all insurance claims in the city are related to theft, arson or other offences, according to a study published by insurance firm Axa today.

Axa said the average claim for a crime-related incident in the first three months of the year was more than #4,000, six per cent higher than a year ago.

It was now #4,179 compared with #3,942 for the last three months of 2005.

Nationwide crime is now costing businesses #700 million a year, the company estimated, with binge drinking, drugs and yob culture being blamed by victims.

But the total number of crime-related claims fell by 24 per cent compared with the last quarter of 2005 and the total value of them dropped by 23 per cent.

Neil Mercer, of Axa, said: "Although our figures show a decline in the number of business crimes, this is still a serious problem that is costing small and medium-sized businesses well over #700 million a year."

Theft is the most common claim and accounts for the largest share of business crime related insurance settlements at 62 per cent, and responsible for 49 per cent of the costs.

Arson is the most financially crippling crime small businesses face, with the offence representing 3.77 per cent of business crime related insurance claims but 38 per cent of settlements.

Birmingham topped the city business crime table with 27.87 per cent of all claims between January and March being crime-related, a 5.5 per cent rise on the last three months of 2005.

The city was followed by Cardiff (26.82 per cent of crime related claims) and Bradford (24.18 per cent).

London experienced a 0.73 per cent dip to register 15.88 per cent of all crime-related business claims being linked to offences, while Liverpool was described as the safest place to run a business.

The number of businesses making insurance claims after becoming the victims of crime fell in Liverpool by 10.68 per cent to 12.83 per cent.

Insp Mark Stokes, business crime advisor to Advantage West Midlands, said: "I don't think Birmingham is the capital of business crime; this goes against a study last year which said the city was one of least affected areas in the country.

"There is a problem, but that is going to be tackled with business crime becoming one of the key performance indicators for West Midlands Police.

"This will see more resources going into reducing commercial burglary, fraud and commercial vehicle crime.

"When you concentrate on offences, you tend to see a temporary reduction. We want to make it a permanent reduction.

"But we also need businesses to help themselves more, and report offences."

John Lamb, spokesman for Birmingham Chamber, admitted it was a concern that Birmingham topped the table, but great strides were being taken in the city to combat crime.

Mr Lamb added that he did not think the survey would dissuade companies from locating in Birmingham.