Outgoing Telecom CEO Paul Reynolds will step down on June 1 and leave the company on June 30, the end of its financial year.
His replacement, Simon Moutter, takes over on September 1 and Gen-i boss Chris Quin will act as interim CEO from June 1.
Reynolds said he was proud to leave Telecom in a healthy state.
"Telecom has successfully navigated the enormous challenges of the past five years and looks forward to great opportunities ahead as New Zealand moves into a world-first industry structure of open access-fibre networks. Telecom is now subject to significantly less regulation which enables the company to focus on delivering for its customers. Shareholders have seen strong benefits and I have no doubt that Telecom will continue to progress and improve," he said.
"I leave Telecom with real gratitude at being given the opportunity to negotiate a reset of Telecom's place in New Zealand and to work with the enormously talented and committed team of people in the company," he said.