The hunt has begun for a new leader at the mental health trust for Norfolk and Suffolk following the resignation of its chief executive.

Aidan Thomas today announced that he was leaving his post at the Norfolk and Suffolk NHS Foundation Trust after four years at the helm.

The chief executive, who has led a restructure of the NHS trust over the last year to reduce more than 500 jobs, admitted that he had struggled with the regular commute from his Essex home and said he was better suited in a smaller organisation.

Mr Thomas, who led the merger between the mental health trusts in Norfolk and Suffolk in 2011, said he indicated his wish to step down several months ago, but remained in post to support the new chairman and complete the trust's service strategy consultation.

He said: 'I have been considering my future since the merger. It is not a decision I have found easy because I feel very privileged and proud to have been the chief executive of such a great trust and to have met so many brilliant and committed staff and colleagues. I've decided that having led the negotiation and external consultation on our service strategy, now would be the right time to step aside and let someone else lead the trust through the changes over the coming years.'

'Those who have worked with me know that I wouldn't ever want to give less than a 100pc in any role, and the trust and our new chairman deserve this. However I do believe my style of management is better suited to a smaller organisation. In addition, I have struggled with the regular commute from my Essex home.'

The trust plans to cut 502 out of 2,128 posts and 20pc of its in-patient beds by 2016 across Norfolk and Suffolk to focus on more care in the community. The changes are a result of a need to meet the government's demands for a 20pc budget cut.

Andrew Hopkins, Deputy CEO of the mental health trust, will take over as acting chief executive from July 1.

Gary Page, chairman, added: 'Aidan told me before I applied for the role of that he was considering his future. Whilst I am genuinely sorry to see Aidan go I fully respect and understand his reasons for doing so. He has transformed the trust and succeeded in building on our foundations of excellent care to bring growth and competitiveness as well as strengthening our external relationships.

'The trust, partly through Aidan's leadership, is well prepared to deal with the challenges ahead and while there is never a good time to lose such a good CEO, we are in a position of relative strength, and we wish him well with whatever he chooses to do in the future.We will start the search for a successor after the summer months.'