Leighton Smith, who has dominated morning radio for more than three decades, says the time is nearing when he will step back from the microphone.
Smith will sign off from his long-held morning slot at the end of next year.
Kerre McIvor, presently the co-host of the afternoon show with Mark Dye, will take over in the morning slot at that time.
Newstalk ZB has also announced that Simon Barnett will take over the afternoon show when he joins the station in early 2019.
Smith said it was time for him to pursue other opportunities.
"After more than one attempt to surrender the microphone, the time is right," Smith said.
"I've been at this one microphone for longer than I would ever have thought. It's been a privilege and pleasure and my gratitude goes to a very loyal audience. But there is a still a year to go," he said.
"I have loved this job. I continue to love this ... it's not a job," he told his listeners this morning.
"I have enjoyed it thoroughly.
"Coming in here five days a week has been fun ... but like I said everything changes."
NZX-listed NZME owns Newstalk ZB and the company's head of talk Jason Winstanley said Smith was "without question one of the most magnificent broadcasters New Zealand has ever seen".
"He has kept his loyal audience abreast of the news, the opinions and the analysis, each and every day. He always leads the agenda. We will miss his intelligence, his wit and, most of all, his incredible voice each morning."
Smith has worked alongside his producer, now wife, Carolyn Leaney for the past 30 years.
