Microsoft is buying the professional networking website LinkedIn for just over $26bn (£18bn).
The software giant said that LinkedIn would retain its “distinct brand, culture and independence”.
Jeff Weiner will remain as chief executive, reporting to Microsoft boss Satya Nadella.
Mr Weiner and Mr Reid Hoffman – chairman, co-founder and controlling shareholder of LinkedIn – both back the deal.
It is by far the biggest acquisition made by the software giant, which has made eight takeovers worth more than $1bn.
Microsoft bought Skype in 2011 and Nokia in 2013.
Copyright: BBC Business