The health service's troubled £12.4bn information technology programme is being overhauled in a move likely to lead to further delays.

David Nicholson, the new chief executive of the National Health Service, has ordered a review both of the scope of the programme and the way it operates.

The review will look at whether the centrally run programme is "too prescriptive" in the products it offers GPs and hospitals. Connecting for Health, which runs the project, is set to be slimmed down, with staff transferred into the NHS locally as it is turned into an executive agency.

Key ambiguities about policy and implementation may finally be resolved four years into the project.

The review comes as Richard Granger, the programme's head, told the Financial Times that a combination of the NHS's financial troubles and the need for more useful software meant the installation of new patient administration systems - already running well behind schedule - were likely to be put back further.

Instead, he said, other elements of the programme would receive greater focus, for example getting digital imaging systems into all hospitals, rolling out electronic prescribing and providing software to help the NHS's new payment system work.

The review is likely to signal a shift in power within the programme as Mr Nicholson appears to take direct responsibility for the project.

Mr Granger, who has argued that policy and operational difficulties in the NHS, rather than IT issues, are largely the reason for the programme's delay, will remain responsible for the IT roll-out.

But as chief executive, Mr Nicholson has now become the programme's senior overseer, seeking to reassure himself that it will provide what the NHS needs, while making sure the service finally comes to "own" it.

Mr Granger indicated he would support such changes. "Sorting out consent [whether patients should be asked before their medical records are uploaded on to the system] is a policy question that is being pinned on me [that] I would say belongs elsewhere [in the department]," he said.

He accepted that Connecting for Health would shrink. "The job is going to take longer, so the team needs to be smaller."