ESB's finance director Donal Flynn is leaving to join Glen Dimplex, Ireland's largest privately-owned manufacturing firm.
After nearly six years at the electricity utility, Mr Flynn will join the Glen Dimplex team as its chief financial officer later this year.
The ESB said the process to appoint his successor would begin immediately, with Mr Flynn, a former SSE Airtricity executive, continuing in his current role to facilitate the transition.
“I am extremely fortunate and proud to have worked as group finance director, for a great Irish company like ESB,2 Mr Flynn said in a statement.
ESB chief executive Pat O’Doherty said: “Donal has made a lasting contribution to the company and given great support to the board and to me as chief executive. We all wish him continued success in his new role”.