Apple's co-founder cut a worrying figure in his t-shirt-tucked-into-jeans uniform during the launch of the iPad2 back in March. So, unfortunately, this will come as a surprise to few.

The 56-year-old released this following statement:

"I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple's CEO, I would be the first to let you know. Unfortunately, that day has come. I hereby resign as CEO of Apple. I would like to serve, if the Board sees fit, as Chairman of the Board, director and Apple employee. As far as my successor goes, I strongly recommend that we execute our succession plan and name Tim Cook (currently the chief operating officer who's been standing in for Jobs recently) as CEO of Apple. I believe Apple's brightest and most innovative days are ahead of it. And I look forward to watching and contributing to its success in a new role. I have made some of the best friends of my life at Apple, and I thank you all for the many years of being able to work alongside you."

Sky's American correspondent Greg Milam said of the announcement: "

"He is, of course, a man who is iconic in the whole Silicon Valley movement, a man who founded Apple. He saved it from near bankruptcy back in the 1990s. He's seen as the real visionary behind those products we now associate with Apple... the man who really drove the creative side of Apple. It will be interesting to see where they go from here, because this is certainly the end of an era for Steve Jobs and a difficult time for Apple, I'm sure."

Steve Jobs founded Apple in 1976 with Steve Wozniak and Ronald Wayne.

According to Sky News, Apple's shares fell 5% in after-hours trading.