Steve Ballmer, who took over as chief executive of Microsoft in 2000 from its co-founder Bill Gates announced Friday that he would retire from the company within the next 12 months, somewhat sooner than he had anticipated and leaving no obvious successor.
Ballmer, who joined Microsoft in 1980, will be departing a company that is very different from the fearsome software giant of the 1990s. During his tenure as CEO, the company has failed to capitalize on some of the most important tectonic shifts in technology, including the rise of mobile devices and Internet search.
Ballmer also watched as Apple, an old nemesis that nearly went bankrupt in the late 1990s, and Google, which didn't even exist until then, have soared.
As chief executive, he has faced regular calls for his ouster from investors and analysts in recent years because of the company's missteps. But Microsoft said the decision to leave the company was entirely Ballmer's.
"There is never a perfect time for this type of transition, but now is the right time," Ballmer said in a statement.
Ballmer, 57, will stay on until a successor is chosen by a special committee of the board that includes John W. Thompson, the board's lead independent director, and Gates, Microsoft's chairman. The committee will consider both internal and external candidates and has hired an executive search firm to scout for a replacement.
This year, Microsoft announced a major restructuring aimed at making the company more nimble and less prone to infighting. Ballmer has said the shakeup will help remake Microsoft into a "devices and services" company, one that pays greater mind to blending its software with hardware — and, in some cases, makes devices itself.
Ballmer said he was leaving earlier than planned because he believed the company needed an executive who would remain well beyond that transition.
"My original thoughts on timing would have had my retirement happen in the middle of our company's transformation to a devices and services company," Ballmer said. "We need a CEO who will be here longer term for this new direction."
The fact that Ballmer announced his plans without a successor in place was puzzling to many observers in the tech industry.
Some analysts speculated Friday that Ballmer announced his retirement early to buy time to find a successor without the distraction of a fight with shareholders.
Microsoft's financial performance in the coming quarters could also have amplified calls for a leadership change.
The company posted disappointing results in its most recent quarter as its venerable Windows business showed signs of succumbing to a broader slump in PC sales. Microsoft also disclosed an embarrassing $900 million charge to cover its unsold inventory of Surface tablets, the company's answer to the iPad.