UPDATE 2-Apple's Jobs takes medical leave, shares tumble

(Adds analysts' comment, stock move, background)

By Gabriel Madway

SAN FRANCISCO, Jan 14 (Reuters) - Apple Inc (AAPL.O) Chief Executive Steve Jobs will take a medical leave of absence until the end of June because his health problems are "more complex" than he had thought, shocking investors and sending the company's shares down as much as 10 percent on Wednesday.

Jobs, a pancreatic cancer survivor, made his bombshell announcement only nine days after he sought to soothe persistent concerns about his health by saying his marked weight loss over past months was due to a hormone imbalance that was relatively simple to treat. [ID:nN05200877]

Jobs said he planned to remain involved in major strategic decisions while he is away. Chief Operating Officer Tim Cook will take responsibility for day-to-day operations in Jobs' absence.

An Apple spokesman declined to elaborate on Jobs' health on Wednesday.

Speculation about his health resurfaced in June 2008, when Jobs appeared markedly thinner at an Apple event. He is seen as the driver of Apple's successful, consumer-friendly products, including Macintosh computers, iPod media players and iPhones.

"It's something we don't need right now. This Apple news gives investors more angst to digest and get through and take itself out of," said Tom Sowanick, chief investment officer of Clearwater Financial in Princeton, New Jersey. "Yes, the markets have (been) building in risks with respect to Steve Jobs' health, but Apple shares will still get hit in the morning."

"Steve Jobs is known as the company but we have to see how well his 'support system' -- the people he put in place -- will hold up," he added.