Shares in LinkedIn dived as talk spread of plans by Facebook to step into its turf with a version of the leading social network tailored for the business world. LinkedIn's share price shed just over US$10 on Monday, dropping by around 4.3 per cent to US$223.71 in the wake of reports that Facebook At Work was being tested with a select cadre of businesses. "At first blush, it seems that Facebook is following the lead of Google and moving from a pure consumer play into the enterprise," said Forrester analyst Rob Koplowitz. "We really don't know how far they intend to go." Facebook at Work could make its public debut in a matter of months, according to a source familiar with the project being led by a team in London. The social network has work-centric spins on familiar Facebook features such as news feed and messaging. It is tailored for workers to collaborate on jobs, and is limited to inside businesses. Information from Facebook at Work is not shared with people's personal social networking accounts. Facebook is not charging fees during the pilot project, which is ad-free, but could roll it out as a paid service for businesses. While a workplace version of Facebook would face challenges, it would be a threat to established services such as LinkedIn, Cisco's Jabber, IBM Connections, Microsoft-owned Yammer, and various tools that Google offers. The prime target would be LinkedIn, the leading social network for making and cultivating work-related connections for goals including finding jobs or employees and advancing careers. "This would be a natural step for Facebook to make," said analyst Rob Enderle of Enderle Group in Silicon Valley. "It is in their area of expertise and it is a way to expand; go after someone else's turf." Reaching into businesses would be a way for Facebook to expand a service that boasts more than a billion users globally but which is believed to have been losing young users. California-based Facebook last month reported its quarterly profit nearly doubled to US$802 million but saw its stock pounded after outlining a plan to invest heavily in the future instead of revelling in short-term riches.