Microsoft COO Kevin Turner jumps ship after 11 years at the software giant

Eleven years under Steve Ballmer and Satya Nadella more than enough for Turner

The turnover of senior staff from Microsoft has continued with the news that its chief operating officer of 11 years, Kevin Turner, is to leave to become CEO and vice chairman at financial services company Citadel Securities.

Turner (pictured) was appointed COO of Microsoft in 2005, prior to which he held various positions at retailer Wal-Mart, including CIO for Wal-Mart Stores. Turner had joined the retailer as a cashier while studying for his undergraduate degree. The previous incumbent of the COO role at Microsoft was Rick Belluzo, who left three years earlier.

As COO, Turner was responsible for the strategic and operational leadership of Microsoft's worldwide sales, including its field marketing and services organisation, as well as managing support and partner channels and corporate support functions - including Microsoft's own IT - as well as licensing, pricing, and operations.

Latterly, he was also responsible for the sales and marketing drive behind Office 365, as well as Microsoft's Azure cloud. In total, more than 51,000 employees across 191 countries ultimately reported to Turner.

In 2009, Turner masterminded Microsoft's entry into retail stores. In addition, he served on the Senior Leadership Team, the internal body that sets Microsoft's overall strategy and direction, and had been an outside candidate as Steve Ballmer's replacement when he stepped down as Microsoft CEO 2013.

While Ballmer was the target of internal ire over the way in which scorecarding turned employees and their teams on each other, it was Turner who introduced the concept to the company. He had also promoted the use of scorecarding to rank employees while at Wal-Mart.

Like in 2002, though, Microsoft isn't planning a direct, like-for-like replacement for Turner. Instead, the company will disperse his responsibilities across a number of senior managers and executives. Turner will stay on at Microsoft until the end of the month, according to an internal email sent by CEO Nadella.