Bruce Robinson, head of the Northern Ireland Civil Service, is set to retire from the job.
A key Government adviser to First Minister Peter Robinson and Deputy First Minister Martin McGuinness, it is understood he has informed them of his decision to step down.
Mr Robinson took up the post in 2008 and is expected to remain in position until March next year, by which time a successor will have been selected.
Mr Robinson is married with four children and joined the civil service in 1982.
A chartered accountant and an economics graduate of Queens University Belfast, he currently leads 25,000 civil servants.
He is also head of the Office of the First Minister and Deputy First Minister, and Secretary to the Northern Ireland Executive, making him the most senior adviser to the First and the deputy First Ministers.
A former permanent secretary in the Department of Finance and Personnel, he succeeded Sir Nigel Hamilton in the lead role in the civil service.
Mr Robinson had previously served as permanent secretary at the Department of Enterprise, Trade and Investment, and before that he had an 18 year career in the Industrial Development Board where he was chief executive between 1995 and 2000.
In August he hit the headlines when it was announced he had taken the unprecedented decision of suspending a permanent secretary of a Northern Ireland government department. Paul Priestly, permanent secretary of the Department for Regional Department, was suspended pending an investigation into controversies surrounding government company Northern Ireland Water.
Mr Robinson, meanwhile, has played a central role in the operation of the public sector during a period of major reforms. When he became head of the civil service, he was credited with having played a key role in improving financial management in Northern Ireland government, particularly in the performance of departments in meeting forecasts.