Apple founder Steve Jobs has resigned as chief executive of the technology giant and will be replaced by its chief operating officer Tim Cook.

Mr Jobs, who underwent a liver transplant following pancreatic cancer, said he could no longer meet his chief executive's duties and expectations, BBC reports.

In a short letter to the board of Apple, Mr Jobs wrote: "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. 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."