Shelagh Fogarty is to leave the BBC 5 live breakfast show in the spring to present the lunchtime show instead.
The presenter, who has fronted the show alongside co-host Nicky Campbell for seven years, announced the news on her Twitter page.
"I'm leaving Five Live Breakfast after 7 amzing yrs working with Nicky. Lunchtime Show frm the Spring."
The lunchtime show is currently hosted by Gabby Logan.
She had already announced she would leave in April 2011 due to other work and family commitments.
Fogarty said: "I'm in the lucky position of leaving a job I love, to start one I'm really excited about. Nicky says he forgives me but I don't believe him! Hopefully he and I can still do programmes together in the future one way or another. I learnt a huge amount just by sitting next to him, and I'll miss him."
Campbell tweeted: "Shelagh is a fantastic broadcaster, special person and amazing friend. I will miss her so much as I know you will. The search is on."
A replacement for Fogarty on the breakfast show will be announced in the new year.
Several listeners responded to 5 live's blog to say they would miss Fogarty in the mornings.
"I am so upset about Shelagh leaving the Breakfast Programme - she is a wonderful broadcaster and I always think what a lovely friend she would make!," wrote mrs_viv.
Fogarty famously rebuked Rage Against The Machine after they swore during a live performance of their song Killing In The Name a year ago.
The band were there to discuss a Facebook campaign to make their song the Christmas number one instead of The X Factor winner Joe McElderry's.
While the song was being faded out, Fogarty was heard saying: "Get rid of it."
She then told her audience: "Buy Joe's record."
Fogarty joined 5 live in 1999. Before that, she worked across the BBC, including the Corporation's Northern networks and Radio 4.
She has also presented other 5 live programmes including Drive, Breakfast, Late Night Live and the Sunday Service.