Microsoft is to acquire Nokia's Devices & Services business, which includes the smartphone and mobile phones businesses, for $3.79 billion euros ($5 billion).

The Redmond, Washington, software company will also pay $1.65 billion euros to license Nokia's patents, for a total transaction cost of $5.44 billion euros in cash, ComputerWorld reports.

Nokia CEO Stephen Elop will be coming back to Microsoft and lead an expanded devices team, Microsoft's CEO, Steve Ballmer, said in an email to employees.

The announcement brings an end to Nokia’s three-decades-long adventure selling mobile phones, as well as speculation about a future sale to Redmond, dating back to the moment Nokia announced a former Microsoft executive, Stephen Elop, would take the reins in September 2010.That speculation intensified five months later when Elop announced a strategic partnership between Nokia and Microsoft, in which Nokia would use Windows Phone as its primary operating system, according to the Forbes.

"Building on the partnership with Nokia announced in February 2011 and the increasing success of Nokia's Lumia smartphones, Microsoft aims to accelerate the growth of its share and profit in mobile devices through faster innovation, increased synergies, and unified branding and marketing," Microsoft said in a statement.

With its devices and services division gone, Nokia will focus on its three remaining core businesses — NSN network infrastructure and services. The company has scheduled a press conference Tuesday at 11am local time in Finland, and an extraordinary-shareholders’ meeting on Nov 19.