Stuart Bell chief executive of the South London and Maudsley mental health foundation trust is to leave his job after 13 years, HSJ can reveal.

Mr Bell, number 84 in the HSJ 100 list of the most influential people in health, has led the UK’s largest provider of mental health services since it was created in 1999.

HSJ has learned he will take on the top job at the smaller Oxford Health Foundation Trust which provides mental health services across Oxfordshire and Buckinghamshire.

The Oxford University graduate has been a leading figure in the development of mental health services in the UK and was awarded a CBE in 2008 for services to the NHS.

He successfully led the South London and Maudsley Trust through its creation and merger and later through its application to become a foundation trust. He has also been instrumental in the development of King’s Health Partners - the only academic health sciences centre with a major mental health involvement.

The former head of NHS Performance has been a crucial part of efforts to bring in payment by results for mental health services as chair of the Department of Health’s expert advisory group.

Before working at South London Mr Bell was chief executive of Thameslink NHS Trust and Lewisham and Guy’s Mental Health NHS Trust. Earlier in his career he worked at Charing Cross and Whittington Hospitals before moving to the South West Thames Regional Health Authority in 1990.

South London and Maudsley NHS Foundation Trust is the largest provider of mental health and substance abuse services for people living across Croydon, Lambeth, Southwark and Lewisham, as well as substance misuse services in Bexley, Greenwich and Bromley, as well as specialist services across the UK.