"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 said in a letter to employees that was released by Apple.

Tim Cook, Apple's chief operating officer, will take over daily operations although Jobs has promised to remain involved in major strategic decisions while he is away.

Jobs is widely viewed as the driving force behind Apple's popular consumer-friendly products such as the iPod and the iPhone.

But the company has been criticised for failing to announce a succession plan.