No reason was given for Job's resignation, but his health problems, including a lengthy medical leave for a liver transplant in 2009 and his gaunt appearances at public events, fueled speculation he would have to give up the everyday running of the company he co-founded in 1976.
In a letter to the company’s board, Jobs said "I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple's chief executive, I would be the first to let you know. Unfortunately, that day has come. I hereby resign as chief executive of Apple”.
Apple, the world's second most valuable company by market capitalization, has appointed chief operating officer Tim Cook as his replacement. Jobs will become chairman of the board.
Jobs is seen as the heart and soul of Apple, with analysts and investors repeatedly expressing concern over how the California-based company will fare without the figure seen as its driving force.
Apple stock price slid more than five percent to ê356.32 in trading that followed news of his resignation and it remained to be seen what the market has in store for the company with the opening bell on Thursday.
Jobs is a living legend in Silicon Valley. He is the beloved creator behind the Macintosh computer, the iPod, the iPhone and the iPad as well as the iTunes online shop.
Jobs left Apple in 1985 after an internal power struggle and started NeXT Computer company specializing in sophisticated workstations for businesses. NeXT was bought by Apple in 1996 and Jobs returned to head the company.
He also co-founded Academy-Award-winning Pixar in 1986 from a former Lucasfilm computer graphics unit that he reportedly bought from movie legend George Lucas for ê10 million.