Antivirus and security software provider Symantec fired Chief Executive Steve Bennett on Thursday, the second time it has sacked its top executive in less than two years, as the company struggles to revive growth amid eroding PC sales.
Shares of the company, known for its Norton antivirus software, fell as much as 10 percent in extended trading.
Symantec said it appointed board member Michael Brown as interim president and CEO.
The company said the decision to let go of Bennett was "the result of an ongoing deliberative process and not precipitated by any event or impropriety.''
"It's a jaw-dropping move, especially because Bennett was key to the company's turnaround. I view this as a major step back ...,'' FBR Capital Markets analyst Daniel Ives said.
"Over the last decade, there have been a lot of head scratching moves at Symantec from strategy to acquisitions and you just add this to the list,'' Ives said.
Symantec unexpectedly ousted CEO Enrique Salem in 2012 even as a strategic review was under way to turn around the company.
A special committee of the board will immediately begin a search for a permanent CEO with the help of an executive search firm, the company said.
Symantec also reaffirmed its earnings and revenue forecast for the fourth quarter.
The Mountain View, California-based company's shares closed at $20.90 on Thursday on the Nasdaq.