Ms Hastings said the decision to double the number of local on-air hours in the region was based on demand for more localism from listeners and advertisers.
"Localism is as strong as ever. We are regularly asked about extending local content, particularly from local businesses who want to talk to locals. This also benefits national advertisers who need to connect locally and in relevant ways."
TRN chief content officer Dean Buchanan said breakfast radio was all about being connected on a local, national and international level.
He said a number of international A-list stars had committed to interviews that will be heard in the coming weeks. "In a globally connected world, listeners demand the very best of entertainment.
"Polly and Grant have proven themselves as both and have an exceptional track record that is world-class.
"The Hits captures all that was strong from Classic Hits and has evolved to recognise today's modern day adult listener."
In Rotorua, Hickey will be followed on air by Stacey Morrison and Justin Brown from 3pm to 6pm and Jason "JT" Tikao from 7pm to midnight.
Green will move to the New Plymouth station.
ZM will focus on a younger audience with its new breakfast team Fletch, Vaughan and Megan (Carl Fletcher, Vaughan Smith and Megan Sellers).
