More than half (54 percent) of chief information officers (CIOs) interviewed recently said their firms do not allow employees to visit social networking sites for any reason while at work.

The survey was developed by Robert Half Technology, a leading provider of information technology (IT) professionals on a project and full-time basis, and conducted by an independent research firm. It was based on telephone interviews with more than 1,400 CIOs from companies across the United States with 100 or more employees.

CIOs were asked, “Which of the following most closely describes your company’s policy on visiting social networking sites, such as Facebook, MySpace and Twitter, while at work?“

Their responses:

    Prohibited completely                                54%
    Permitted for business purposes only                 19%
    Permitted for limited personal use                   16%
    Permitted for any type of personal use.              10%
    Don't know/no answer                                  1%
                                                        ---
                                                        100%

“Using social networking sites may divert employees’ attention away from more pressing priorities, so it’s understandable that some companies limit access,” said Dave Willmer, executive director of Robert Half Technology. “For some professions, however, these sites can be leveraged as effective business tools, which may be why about one in five companies allows their use for work-related purposes.”