Microsoft CEO Ballmer To Retire Within 12 Months

SEATTLE/NEW YORK: Microsoft Corp Chief Executive Steve Ballmer unexpectedly announced his retirement on Friday, ending a controversial 13-year reign as the head of the world's largest software company and sending the company's shares up 7 percent.

Ballmer, 57, a close friend and confidant of co-founder Bill Gates since the company's earliest days, took over as CEO in January 2000. During his tenure Microsoft's revenues tripled but he's long been a target of criticism from Wall Street and Silicon Valley as the company's share price stagnated and rivals Apple Inc and Google Inc led a mobile computing revolution that has upended the global technology industry.