Apples chief executive Steve Jobs is to take a six-month break from running the business to focus on his health. Speculation had been mounting over the increasingly gaunt appearance of the Apple chief, which earlier this month was revealed to be caused by a hormone imbalance. However in an open letter to Apple employees, Jobs said his health-related issues were more complex' than he thought. 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," he wrote. "In addition, I have learned that my health-related issues are more complex than I originally thought. 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. Jobs also revealed he had asked Tim Cook to take over the running of Apples day-to-day operations. He said he planned to remain involved in major strategic decisions while he is off.