SAN FRANCISCO — Microsoft chief executive Steve Ballmer isn’t going to let anyone get in his way.
Not even his presumed heir apparent, who runs the software maker’s Windows empire, can stop Ballmer as he pushes the company in a new direction.
That was the underlying message of a power struggle that led to the abrupt departure of Steven Sinofsky, who oversaw the Windows operating system that has been the foundation of Microsoft’s success.
The fissure disclosed late Monday came less than three weeks after Sinofsky and Ballmer appeared on a stage in New York to hail the long-awaited release of Windows 8, a radical overhaul of the operating system.
The Redmond, Wash.-based company designed it to make its products more relevant in an age when more daily computing tasks are shifting from desktop and laptop machines to smartphones and tablet computers.
Microsoft Corp. did not elaborate on the reasons behind the end of Sinofsky’s 23-year career at the company.
But all signs pointed to tensions boiling over as Ballmer tries to weave Microsoft’s products more closely together so the technology is easily accessible whenever and wherever people want to work, play, and communicate.
That is a goal Microsoft rivals Apple Inc. and Google Inc. have been pursuing for the past few years, giving them a head start in a battle that is immersing technology even deeper into people’s lives.
To achieve his objectives, Ballmer is trying to dismantle fiefdoms within Microsoft that date back to the 1990s when cofounder Bill Gates ran the company. According to industry analysts, Gates divided the company into different engineering silos devoted to each of Microsoft’s key franchises — Windows, the Office suite of software, online services, and corporate servers.
When Ballmer became chief executive nearly 13 years ago, he inherited the structure and even expanded it to include new divisions to house new products such as the Xbox 360 gaming console.
Now that Ballmer is trying to tie Microsoft’s operations more closely together, he is likely facing resistance from company veterans such as Sinofsky, said longtime technology analyst Rob Enderle.
‘‘Sinofsky is an empire builder who is not going to look kindly at someone coming in and telling him he has got to start sharing,’’ Enderle said. ‘‘But Ballmer needs everyone to do the Kumbaya thing and come together. They were likely increasingly bumping heads in terms of the future of the company.’’
As part of Ballmer’s strategy, Microsoft is expanding beyond software into device making. The company’s first tablet computer, the Surface, went on sale with the release of Windows 8 and now there is speculation that Microsoft may also make a smartphone, too. By selling hardware, Microsoft risks alienating the device manufacturers who license Windows 8.
Ballmer, 56, isn’t the only chief executive facing friction within the ranks. Last month, Apple chief Tim Cook said he was replacing Scott Forstall, a longtime company executive in charge of the software that runs the iPhone and iPad.
Like Sinofsky at Microsoft, Forstall was considered to be a leading candidate to become Apple’s next chief executive.
Sinofsky’s departure will likely increase the pressure on Ballmer as he tries to restore some of the luster Microsoft has lost during his tenure. The company’s stock price has been depressed for years, largely because investors are not convinced Microsoft will make the technological leap needed to accelerate its revenue growth once again.
The shake-up did not go over well on Wall Street. Microsoft’s stock price fell 90 cents, or 3.22 percent, to close Tuesday at $27.09.
The sell-off may reflect worries that Sinofsky’s departure could be tied to some perceived shortcomings in Windows 8. But analysts say it is far too early to draw any conclusions about how Windows 8 will fare in the market, making it unlikely Sinofsky’s exit has anything to do with the new operating system.
Sinofsky, 47, had been widely seen as Ballmer’s likely successor. After he joined the company as a software engineer in 1989, Sinofsky eventually became a technical adviser to Gates and later oversaw the Office package that includes word processing, spreadsheet, and e-mail programs. He took charge of Windows in 2006 and helped the company recover from the buggy Vista version of the operating system with the release of Windows 7 in 2009. More than 670 million licenses of Windows 7 have been sold since then.
Sinofsky ‘‘is a good manager and a guy known for getting things done, but if you are looking for someone who plays well with others, he is not your guy,’’ Enderle said.