Telecom group counsel Tristan Gilbertson has resigned to seek "his next challenge outside of Telecom".
Gilbertson had been in the position since 2008, overseeing legal, communications, and regulatory matters.
Chief executive Simon Moutter said he would consider how the functions could best be provided now Telecom was a "retail-focused service provider".
Telecom corporate communications manager Ian Bonnar resigned last week. A source said Moutter - who took up the helm at Telecom just seven weeks ago - was rumoured to have a new head of communications in mind.
A spokesman said Bonnar would depart at the end of the year.
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