Granger said: "My decision should be seen in the context of the changing role of the centre of the NHS and the fact that when I took on this challenge I said I would give this job five years.
"There remain a number of challenges ahead, but I firmly believe that the leadership of the programme by Lord Hunt, David Nicholson and my colleagues within Connecting for Health will ensure these hurdles are overcome."
An announcement regarding the identification of a successor, and of transitional arrangements will be made by the Department of Health in due course, the department said in a statement.
Tony Collins' blog
Computer Weekly's award winning investigative reporter gives the inside scoop on government IT
Comment on this article: email@example.com