UK firms are at risk of data leakage through employees' increasing use of Web 2.0 technologies and social-networking websites, security experts have warned.

A survey of more than 1,000 office workers found that 42 percent of those aged between 18 and 29 discussed work-related issues on social-networking sites and blogs.

The research, carried out by polling company YouGov for content security specialists Clearswift, revealed more than a quarter of young workers spent three or more hours a week surfing blogs and sites such as MySpace and YouTube during working hours.

Nearly four in ten admitted accessing such sites "several times a day".

Younger employees are more likely to take access to such sites for granted, with 59 percent of office workers aged 18 to 29 believing staff should be able to use their work computers to visit these sites for personal reasons, compared with 38 percent of staff aged over 30.

Clearswift chief operating officer, Ian Bowles, said the research shows organisations need to look closely at the social media sites their employees are using at work to ensure sensitive business issues or information is not being discussed.

"However, finding the balance between harnessing so-called 'Web 2.0' technologies for business benefit and maintaining strong security is key," he added.

Bowles added: "It isn't difficult to envisage an employee posting unauthorised comments about their organisation's product or service quality issues on a blog - causing major brand damage - but at the same time, banning all blog access is not the answer as it cuts the organisation off from conversations with partners and customers."

Frost & Sullivan analyst, Katie Gotzen, said: "Whilst organisations have woken up to the security risks with email traffic, this awareness is not always extended to the bi-directional communications which are common in Web 2.0. Yet social-networking sites and blogs carry an even greater risk for data leakage and brand damage than email, because anyone can potentially access them."

The survey found most office workers were aware of their company's policy on employee use of the internet, with just 14 percent saying they did not know if one existed or not. More than a quarter of those surveyed said their organisation did not allow access to social media sites with 14 percent saying their company had no policy at all.