Teresa Elder, Vodafone Ireland's chief executive, has decided to leave the company at the end of the year for personal reasons.
A statement from Vodafone Ireland says that Ms Elder's son, who has cystic fibrosis, has been hospitalised in the US and that she and her husband has decided to return to the US to help him.
The company said it has started a process to appoint her successor.
'The Irish mobile market is one of the most exciting in Europe and I have thoroughly enjoyed my time here as we have brought leading edge services to our customers', commented Ms Elder.
'However, it is very important for me to be back in the US and I would like to thank the company for the support they have shown me in reaching this decision,' she added.
