Mau announced in a tweet that she was leaving the 7pm show, and soon after it was confirmed Breakfast host Toni Street and Hosking, Newstalk ZB's breakfast host, would join Jesse Mulligan at Seven Sharp.
Mau insisted only days ago she was staying with the show. She will join Radio Live next year, appearing alongside Willie Jackson in a new afternoon programme. Hosking will remain with ZB, and a search has started to find a replacement for Street on Breakfast.
The future is less clear for Tamati Coffey, who had been filling in on Seven Sharp after the departure of Greg Boyed, but will not return for the 2014 season.
TVNZ head of news and current affairs John Gillespie said yesterday: "Ali has been an integral part of launching Seven Sharp and the show has benefited greatly from her involvement."
The new Radio Live show will replace the one hosted by Jackson and John Tamihere. The pair were taken off air at the height of the Roast Busters scandal after a controversial interview with a teenager.
Tamihere will not be back; instead Jackson will partner with Mau. The general manager of talk brands for MediaWorks Radio, Jana Rangooni, said Mau was a "hugely talented broadcaster".
"She's smart, has strong opinions, a great sense of humour and the dynamic between her and Willie will create great talk radio."
TVNZ denied plans to overhaul Seven Sharp's content, which critics have labelled lightweight infotainment.
Mr Gillespie said Seven Sharp would not only keep its name but also its entertainment-style approach.
"Seven Sharp has been a bold departure from legacy format current affairs at 7pm," Mr Gillespie said.
Bill Ralston, former head of news and current affairs at TVNZ, said the Seven Sharp shake-up could help address the show's balance of current affairs content versus entertainment.
"As long as they have at least one segment that covers something reasonably seriously they're probably okay."
Ralston was surprised to hear Mau was teaming up with Jackson on Radio Live - but he said the pair had potential.
"He's not a metrosexual male and Ali has her own attitudes to life and feminism, so potentially a real good duo, I think Radio Live is getting it right.
"As long as they don't kill each other."
