Telecom's head of retail Alan Gourdie will leave the country's biggest listed company at the end of October, just two months into the telecommunications group's new era under a new chief executive.
His resignation is effective October 31. No reason was given for his departure in a statement from the company.
He led Telecom Retail, which operates calling, access, mobile and data services to households and small and medium size enterprises, for four years.
Incoming chief executive Simon Moutter will appoint a new head of retail after he picks up the reins on August 31, Telecom said.
"We now have the customer focus and brand required to be a highly competitive retail service provider in the new world of telecommunications," Mr Gourdie said in a statement.
"The company has a bright future after demerger and I am pleased to be leaving the business with very good momentum."
Mr Gourdie follows former Telecom boss Paul Reynolds out the door. He left at the end of June after the company successfully carved out its network into a separately listed entity, Chorus.
During his tenure he has had to contend with a new mobile entrant, Two Degrees Mobile, snatching customers from both Telecom and Vodafone New Zealand with cheaper pricing, tougher regulation of mobile pricing, and a faulty launch of its XT network.
The shares rose 1.7 per cent to a four-year high $2.70, and have jumped 28 per cent this year.