Consultancy firm Morse has renewed calls on firms to create and enforce tighter acceptable usage policies, after new research found that unregulated use of social networks could be costing UK firms over £1.3bn a year in lost productivity.

The firm polled over 1,400 office workers and found that 57 per cent use social networking sites during the working day for personal reasons, while three-quarters said that their employer had not issued specific guidelines for Twitter use.

"Social media can be good for business, helping to extend ties with customers and employees, but organisations don't seem to understand that it's not being used predominantly for business but for personal use. This is a massive productivity black hole," said Morse consultant Philip Wicks.

"Companies need to reinforce a corporate usage policy to ensure that people use their PCs responsibly and predominantly for business purposes."

The survey also highlighted the worrying dangers of staff posting potentially sensitive information on social networking sites. Morse found that 84 per cent of workers believe that it should be up to them what they post online, despite the potential damage to reputation or even share price.

"Acceptable usage policies need to be drawn up by businesses, but they also need to be enforced by IT. It has to be collaborative," said Wicks.