In a surprise deal, Microsoft has agreed to buy LinkedIn, the world’s biggest professional networking site for $26.2bn (£18.5bn) in cash.

The tech giant has agreed to pay $196 (£139) per share for the company, announcing the deal before the market opened on Wall Street and sending LinkedIn’s shares up 49% to $194.55 PMT. Microsoft’s shares fell by 4.2% to $51.48.

LinkedIn, which has over 430 million users worldwide, is a networking site that is designed for people to connect with other professionals and gain access to a range of job opportunities. Microsoft are hoping that the move will expand its reach into the professional networking area.

The deal is Microsoft’s biggest acquisition to date, beating the $8.5 billion Skype deal in 2011 look small in comparison. Microsoft have made clear that LinkedIn will “retain its distinct brand, culture and independence”; Jess Weiner, who will remain as LinkedIn’s chief executive, said the deal “gives us a chance to change the way the world works”