Apple CEO Steve Jobs announced Wednesday that he will take a leave of absence until the end of June because of health concerns.
Jobs recently attributed recent weight loss to a treatable "hormone imbalance," but an e-mail announcement to all Apple employees suggested the problem could be more serious.
"During the past week I have learned that my health-related issues are more complex than I originally thought," Jobs said in the e-mail, addressed simply to "Team."
Jobs, a Palo Alto resident who co-founded Apple in 1976, is universally recognized as the public face of the Cupertino-based company. He announced his leave in a succinct e-mail.
"Unfortunately, the curiosity over my personal health continues to be a distraction not only for me and my family, but everyone else at Apple as well," Jobs wrote.
Speculation about Jobs' health has been rampant over the past year, fueled by his weight loss and his decision not to attend last week's Macworld convention. Jobs was diagnosed with pancreatic cancer in 2003 and had surgery to remove the tumor in 2004.
Tim Cook, Apple's chief operating officer, will take over day-to-day operations, Jobs wrote. Cook had led the company while Jobs was undergoing surgery in 2004.
Jobs said he plans to remain involved in "major strategic decisions" while he is on leave.
Apple's shares fell by $2.38, or 2.71 percent, Wednesday and were listed at $85.33 at the end of regular-hours trading day.