Steve Jobs worries Apple backers with another health scare

Apple boss Steve Jobs spooked investors today by announcing he was taking another medical leave to focus on his health.

Shares in the company tumbled nearly 8% in Europe amid concerns about its hugely influential founder's wellbeing.

In 2009, he underwent a liver transplant that took him out of action for five and a half months, and in 2004 he had treatment for pancreatic cancer.

Jobs, 55, wrote in an email to staff that he would remain chief executive officer although chief operating officer Tim Cook would take on the day-to-day running of Apple.

"I love Apple so much and hope to be back as soon as I can," he said, adding that he would continue to be involved in "major strategic decisions".

The company is working on a second generation of its hugely popular iPad, and Jobs was expected to reveal the gadget to press within weeks. New versions of the iPhone are also expected over the summer.

Jobs was also set to appear alongside Rupert Murdoch in the next few weeks to launch News International's iPad-only newspaper, The Daily.

Jobs' health has been an obsession in Silicon Valley and among investors concerned about the huge importance of one man to the future of the company.

He is seen as an inventor and visionary in the computing world and combines extraordinary technical nous with a deep understanding of design.

Analysts have fretted during previous health scares that without him, the company would lose the innovative edge that has repeatedly enabled it to come up with new products to revolutionise the computing market.

Further details on the nature of his latest health issues were not forthcoming from the company, which merely published in full the email he sent to staff.

"Team, At my request, the board of directors has granted me a medical leave of absence so I can focus on my health," he wrote.

He added: "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." Signing the email off as "Steve", he requested privacy for himself and his family.

Some analysts pointed out that Apple now had sufficiently expert management to cope without the talismanic founder.

Richard Windsor, global technology specialist at Nomura, said while the underlying state of the company would not be affected by the announcement, "perception is another matter. Steve Jobs is seen by the market to be a major force in Apple's strategic direction. If his pancreatic cancer has returned, one could be quite worried."

Ben Wood, head of research at CCS Insight, said: "The knee-jerk reaction is likely to be negative. However, I think that Apple is clearly a much bigger company than one person."