Microsoft ousts ex-Nokia CEO Stephen Elop, combines OS and devices teams

Elop's exit from Microsoft is actually his second departure from the Redmond, Wash., software giant, as he headed its Business Division responsible for the Office Suite from 2008 to 2010. He was then recruited by Nokia in September of 2010 to take over the struggling smartphone maker.

While at Nokia, Elop issued his famous "Burning Platform" memo in which he announced the Finnish handset company would switch from its own Symbian operating system. Nokia eventually settled on embracing Windows Phone, the mobile platform of Elop's ex-company, Microsoft.

The switch to Windows Phone was too little, too late for Nokia, however, and the company spun off its smartphone division in a $7.2 billion sale to Microsoft in 2013. That acquisition meant that Elop had come full circle, and was back at Microsoft under the title of vice president in the company's Devices and Services business.

At one point, Elop was even seen as a candidate for CEO of Microsoft to replace then-Chief Executive Steve Ballmer. But instead the company named veteran executive Satya Nadella as its next CEO in February of 2014.

Along with Elop, Kirill Tatarinov and Eric Rudder will depart after "a designated transition period." Their departures are related to the engineering restructuring changes, while Chief Insights OFficer Mark Penn is leaving in September for "another venture outside Microsoft."

Microsoft said on Wednesday that its new structure will focus on "enabling more personal computing experiences powered by the Windows ecosystem." The new head of the Windows and Devices Group is Executive Vice President Terry Myerson.

"We are aligning our engineering efforts and capabilities to deliver on our strategy and, in particular, our three core ambitions," said Microsoft Chief Executive Satya Nadella. "This change will enable us to deliver better products and services that our customers love at a more rapid pace."