Apple co-founder and chief executive Steve Jobs announced Monday he was taking a medical leave of absence, 18 months after returning to the company following a liver transplant.
"At my request, the board of directors has granted me a medical leave of absence so I can focus on my health," Jobs said in a three-paragraph email to Apple employees which did not specify his latest health issues.
Jobs, 55, the Silicon Valley legend behind the Macintosh computer, the iPod, iPhone and iPad, said he would continue as chief executive "and be involved in major strategic decisions for the company."
He said chief operating officer Tim Cook, who took over when Jobs went on nearly six months of medical leave in January 2009, would be "responsible for all of Apple's day to day operations" during his absence.
"I have great confidence that Tim and the rest of the executive management team will do a terrific job executing the exciting plans we have in place for 2011," he said.