Apple's Steve Jobs takes medical leave

Apple's chief executive Steve Jobs is to take a six month medical leave of absence, after learning that his health problems were "more complex" than previously thought.

Last week, Apple's head finally opened up about his much speculated-upon health, with Jobs admitting that he had a hormone imbalance that caused him to lose weight.

Yesterday, Apple confirmed that Jobs had sent an email around to his employees, explaining that he'd be back by the end of June. "In order to take myself out of the limelight and focus on my health, and to allow everyone at Apple to focus on delivering extraordinary products, I have decided to take a medical leave of absence until the end of June," he wrote.

During that time, Tim Cook will handle Apple's day-to-day management, but Jobs stressed that he would "remain involved in major strategic decisions" while on leave. Cook previously took over that role when Jobs was diagnosed with cancer in 2004.

Jobs also suggested in the letter to his staff that he wasn't just temporarily leaving over health concerns, but partially because of the attention it was receiving. "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."

Despite the plan for Jobs to return this summer, this will likely fire speculation about Apple's as-of-yet unknown succession plan.

"It's the classic blind man feeling around the elephant. We are all dealing on partial information," said Collins Stewart LLC analyst Ashok Kumar. "There's no individual or even a management team that can fill his shoes."

Another analyst suggested Cook is likely to be the choice. "The next six months are going to be basically a trial period for Tim Cook to be CEO," said Brian Marshall at Broadpoint Amtech."If that period goes well, my expectation is that Steve will pass the baton over to Tim in June and basically Steve will be his senior adviser."

But others warned that Apple could face trouble without Jobs. "Apple is more dependent on its CEO than most other companies," said Roger Kay of Endpoint Technologies. "Steve is a critical judge of the company's business, and that maestro role that he performs is what makes Apple great. But there is no maestro-in-training to take over Steve's role."

Additional reporting by Reuters.