Nearly half (48 percent) of UK firms have banned staff from using social networking sites from their work machines in the past year, says HCL Technologies.

Research carried out by the IT development company in conjunction with Lewis PR revealed 63 percent of staff admitted they had been actively discouraged to use sites such as Facebook and Twitter. However, staff believe it's more because bosses are concerned their reputations may be called into question on social networks rather than lack of staff productivity that's the motive behind discouraging use.

More than two in five (45 percent) of employees admitted they thought their boss was worried derogatory comments about the firm would be posted on social networks.

"It is quite remarkable that in this day and age, many employers are still putting their employees' interests as a low priority by not allowing them to use sites like Facebook," said Vineet Nayar, CEO of HCL Technologies.

"Facebook is such a popular application that is so widely used for personal and business uses, it makes no business sense to ban it. If companies do not address this they could be at the mercy of corporate suicide."