The Department of Health's interim chief information officer Matthew Swindells is to leave the department and the NHS for the private consultancy Tribal.
A DH spokesman said Mr Swindells, who has been doing a review of NHS informatics for NHS chief executive David Nicholson, would leave the department "shortly".
The DH is still trying to recruit a new chief information officer at director general level.
Tribal is one of the DH-approved suppliers of commissioning services under the framework for procuring external support for commissioners. The DH spokesman said Mr Swindells' external appointment had been approved under the rules governing civil servants' move into private sector posts, which are designed to prevent conflicts of interest.
HSJ understands that Mr Swindells has completed his review of NHS informatics. The report is expected to contain strong criticisms of the general informatics programme to date. A spokeswoman for the DH said the report would be published "later in the spring".
Mr Swindells' move followed news that Richard Jeavons, director of IT implementation at NHS Connecting for Health, will leave to become chief executive of the independent reconfiguration panel.
The post at the independent reconfiguration panel was vacated at Christmas when Tony Shaw retired. The panel adjudicates on controversial local service reconfigurations. Mr Jeavons' move comes at a time when the panel's profile is expected to grow as trusts look to centralise specialist services while moving more routine activity into local health centres and polyclinics.
Last month the panel rejected proposals by Oxford Radcliffe Hospitals trust to downgrade services at Horton Hospital in Banbury.
Mr Jeavons plans to stay in his current post until a successor is found.
NHS chief executive David Nicholson said he had "done a great job".
"He will be missed for the energy and enthusiasm he has brought to the programme and his significant contribution to its development, in particular his strong focus on the needs of staff and patients."