Simon Cashmore, who took up the post last November, will be replaced by Linda Kidd.
The announcement was made in a trading update from Nord Anglia's board on the group's businesses on Monday.
Andrew Fitzmaurice, chief executive of Nord Anglia, said, 'Simon's done some good things and has decided to move on to pursue other private equity interests. He leaves with our best wishes.'
Mr Fitzmaurice said that Ms Kidd was previously chief executive of one of Nord Anglia's Connexions businesses and had worked on Nord Anglia's school inspections remit with Ofsted.
The trading update said, 'The nursery market continues to be difficult, demonstrated by a number of our competitors reporting substantial losses in recent months. Consequently, we do not anticipate substantial improvement in the year ahead against the exceptionally difficult market.'
Nord Anglia also confirmed that five of its 98 nurseries would close at the end of September (Nursery World, 31 August).