Apple Inc's Steve Jobs said the board has granted him medical leave to concentrate on his health.
Apple stock fell as much as 7 percent on the Frankfurt Stock Exchange following the news.
At my request, the board of directors has granted me a medical leave of absence so I can focus on my health. I will continue as CEO and be involved in major strategic decisions for the company, Jobs said in a letter.
During his leave of absence, Chief Operating Officer Tim Cook, will be responsible for day to day operations, the CEO said in a media statement.
Jobs will continue as CEO and be involved in major strategic decisions for the company.
Jobs did not say for how long he would be on leave but said that he hopes to be back as soon as I can.
Jobs had stepped away from his duties in January 2009 for health reasons, although he remained involved in major strategic decisions. Cook took over day-to-day operations then too.
Jobs, a pancreatic cancer survivor, underwent a liver transplant while on leave, returning to the company in late June.
Apple is due to report its fourth quarter results after market close on Tuesday.
(Reporting by Sweta Singh in Bangalore; Editing by Savio D'Souza.)