The Secretary General to the Government, Dermot McCarthy, is to step down.
In a letter to colleagues, Mr McCarthy said his term ends in a few months and the Government has already begun the process of selecting a successor.
Mr McCarthy also told staff in his department that a new post of Second Secretary General was to be created.
The new appointment would support the Government's Economic Management Council, as well as playing a role in co-ordinating relations with the European Union and helping Tánaiste Eamon Gilmore in his duties.
Expressions of interest are being sought across the public service for the two posts, and the Secretary General of the Department of Public Expenditure and Reform within the Department of Finance in June.
