Facebook is preparing a new office version of its social networking site to compete with other sites like LinkedIn.

The Financial Times, citing sources familiar with the matter, has reported: “Facebook is secretly working on a new website called ‘Facebook at Work'” that would allow users to “chat with colleagues, connect with professional contacts and collaborate over documents”.

Facebook last month reported its quarterly profit nearly doubled to $US802 million ($A867.73 million) but saw its stock pounded after outlining a plan to invest heavily in the future instead of revelling in short-term riches.

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Facebook, which has 1.35 billion monthly active users worldwide, was founded in 2004 by Mark Zuckerberg with fellow students at Harvard University who wanted to set it up as a college networking site.

The site has been seeking to broaden its offerings, unveiling an application that lets people chat anonymously in virtual “rooms”, evoking the chat rooms from the early days of the internet.

It is also testing a feature that lets users make purchases by simply pressing an on-screen “Buy” button.

Facebook completed its multibillion-dollar deal for mobile messaging application WhatsApp last month.