Apple CEO Steve Jobs has stepped down from his position citing health reasons, in a move that stunned both the tech community and the company’s shareholders.

The 53-year-old Apple veteran, who is widely considered to have revitalised the company and the consumer technology industry with famous brands such as the iPod and iPhone, announced to employees in letter that he would be taking medical leave of absence until June.

Jobs told the press on 5 January that he was being treated nutritionally for a hormone imbalance, but in his letter said: “During the past week I have learned that my health-related issues are more complex than I originally thought.”

The CEO said that he would continue to be involved “in major strategic decisions,” while adding that “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”.

Apple suspended shares prior to Jobs’s announcement, which plummeted 10% immediately after being reopened.

Apple’s COO Tim Cook will take over the running of the company during Jobs’s absence, as he did four years ago when Jobs was treated for pancreatic cancer.