NHS London chief executive Dame Ruth Carnall, one of the service’s most senior and respected leaders, is to leave the NHS next year.

Dame Ruth told HSJ she would not be applying for the role of director of the NHS Commissioning Board’s London sector. She said she had no plans for another job in the service.

She was the highest placed strategic health authority cluster chief executive in last year’s HSJ 100 list of the most influential health service leaders. She has also been recognised for successful London-wide service changes in recent years, particularly in stroke services.

Dame Ruth said she would stay in the post until the end of March next year when the SHA will be abolished, and had no plans for another role. She was a freelance consultant for several years before joining NHS London, and indicated she could work independently again.

She said her priorities were now helping current staff find roles in the reformed NHS system, and “making sure we don’t lose any momentum” on current plans for improving services.

She highlighted work on improving cancer services. She said: “I want to make sure people continue to focus on taking forward changes and improvement.”

Dame Ruth said: “It is extremely sad [to be leaving] but everybody has to change at some point. But I have a fantastic team here and I want to make sure as many as possible have prominent jobs in the new system, and can continue to take forward some of the changes we have initiated, albeit in a different way.”

She said she decided to leave rather than become the board’s director for London partly because she would be inclined to “see it as the old [SHA] job”. The commissioning board’s sectors will differ significantly from SHAs, for example they will have much less autonomy, and will probably have little role in leading service change.

Dame Ruth said: “I think it is time for somebody new.”

Concern has already been voiced about senior and experienced NHS leaders leaving the service because of the commissioning reforms. The exit of very senior leaders could lead to immediate concerns about maintaining service performance and financial stability.

Dame Ruth said: “There is plenty of talent in the system to come forward. It will be difficult immediately but you will find there are lots of talented people who will come forward.

“It is a bit like rose bushes – unless you cut them back from time to time you don’t get decent flowers.”