New talent such as Mikey Havoc, Martin Devlin and Matt Heath was brought in. Older listeners left, but the target audience of men aged 20-44 increased. Overall, the audience rose.
"Hauraki was an iconic brand that had lost its way," Hastings said. "The Hauraki playlist had evolved and was appealing to people aged over 39, and we brought it back."
Hastings said it was early days and she had benefited from a relatively buoyant period of advertising sales.
TRN "has a lot of work to create a new buzz to support creative talent".
A big radio advertiser approached by the I said that competitor MediaWorks - which controls the other half of the commercial radio market - had a reputation for being more nimble, but Newstalk ZB was improving.
Hastings said other TRN stations would be getting a brush up.
"Newstalk ZB has been and is one of our best assets - but when you know something is good, sometimes you just think you can let it roll."
TRN had been looking at introducing new talent on Newstalk ZB, she said. Across the company, radio personalities and their views would take a greater role, with personalities' views of products and places a valuable part of selling.
For instance, she said the likes and dislikes of ZM/FM breakfast host Polly Gillespie on fashion and retail outlets were relevant to advertisers. She could be considered "New Zealand's Oprah", Hastings said.
She stressed that presenters' commercial views had to be genuinely held.
• The Radio Network is half-owned by APN News & Media, publisher of the Herald.
Jane Hastings
Media roles
*The Radio Network chief executive, from September 2012
*AHL Group entertainment general manager, 2010 to 2012, overseeing cinema chains in NZ and Australia
*Group general manager SkyCity Cinemas New Zealand, 2007 to 2010.