Most companies do not stop staff from downloading music from the Internet, despite the risks posed to work computers, a survey has found.

Two-thirds of IT managers polled said they do not block employees from taking music off the Web, even though they named it as the biggest threat.

In a poll of more than 1,000 computer managers by ICM, music came top of the list of perceived threats.

More than half said they feared that music files and other security threats could spread viruses that may lead to fraud or damage corporate computer networks.

Other top 5 threats included staff visiting popular social networking Web sites such as Bebo, MySpace and Facebook.

Internet security firm McAfee, which commissioned the survey, said bosses have the tricky task of protecting computers and stopping time-wasting, while upholding staff morale.

Ultimately, those polled believe this could have a significant financial risk, McAfee said in a statement.

(Reporting by Peter Griffiths; Editing by Steve Addison)