Statistics released by the Confederation of British Industry state that the average British worker spends 90 minutes a week surfing the internet for personal use at a cost of £10.6 billion to the economy.

A handful of firms stated that they have had to sack staff for serious abuse, while others view it as a motivational perk, according to the research.

Nearly 60 per cent of employers think staff regularly use social networking sites, web email and shopping websites outside of lunch hours and formal breaks for web browsing.

It is estimated by employers across both public and private sectors that 4.4 per cent of working time is lost through this activity, which is believed to equate to an average annual cost of £939 per employee.

John Cridland, CBI deputy director-general, said: "Employers need to decide for themselves what level of non-work surfing is acceptable and then set out clear boundaries."

Over half of the 502 companies surveyed restrict access to the internet at work, although only 14 per cent stated that they deny access altogether.

It was reported last year that several big companies including British Gas, the Metropolitan Police and Lloyds TSB had installed internet filters that block staff from using social networking sites like Facebook.

A recent Connect survey found that the two major concerns about outsourcing services like IT support were 'loss of control' (56 per cent) and 'budget over-runs' (43 per cent)