Key Points:

The Radio Network is rebranding Viva as Easy Mix as its rival The Breeze tries for a bigger foothold in the Auckland easy-listening market.

TRN says the Viva name, established two years ago, was being confused with other products and services using the same name.

"Research over the last several months confirmed that there's a degree of confusion," says John Taylor, operations manager for the Classic Hits and Easy Mix Networks.

TRN acknowledges the name change and adjustments to the format is unusual immediately before aratings survey, which begins onSaturday. Taylor and TRN director of programming and marketing David Brice said the timing was so promotional activity around the survey could double up with the soft relaunch of the brand.

Brice said TRN was changing Viva to Easy Mix in stages with pre-recorded and localised segments that would not be heard in other areas it broadcasts in the Bay of Plenty and Hawkes Bay.

"It means we will be able to talk about the weather in Auckland without annoying listeners in Hawkes Bay," said Brice.

He said Easy Mix would continue alongside TRN's other music stations for 25 to 54-year-olds - Classic Hits which plays music from the 80s, and the older focused Coast.

The battle for easy-listening audiences will be important this survey. It gives The Breeze owner MediaWorks the opportunity to dent TRN's dominance of the Auckland market.

When MediaWorks started the Breeze last year, Viva's listener share dropped 7.6 per cent and The Breeze nudged one place ahead in the list of most popular stations .

The Breeze is 11th most popular station in Auckland but is fifth in Christchurch and first in Wellington.

In Auckland the commercial radio market is dominated by TRN-owned NewstalkZB. MediaWorks' launch of The Breeze last year marked a significant move on Auckland whereit has been under-represented. MediaWorks has done heavy cross-promotion for The Breeze on TV3.

Radio listenership surveys are critical because significant changes can influence how much broadcasters can charge for advertising spots.

This survey could show dramatic changes.

Surveys are usually held every six months but the radio industry canceled the March 2007 survey, claiming maintenance work on Auckland's Sky Tower could disrupt transmission.

Martin Gillman, managing director of media buying agency Total Media, said the fact there was a 12-month gap since the last survey instead of the normal six months meant there could be a more dramatic change.

Apart from the battle for easy-listening Auckland, Gillman said that the survey was "all important" for MediaWorks' RadioLive.

RadioLive had parted company with its breakfast host Martin Devlin and took a bold step appointingMarcus Lush.

"RadioLive really needs to do something in this survey," he said.

MediaWorks insists that RadioLive is trading profitably but industry insiders said that MediaWorks had been surprised at how hard it was to break NewstalkZB's dominance.

Elsewhere, media have speculated that MediaWorks is considering revamping its portion of Radio Pacific to create a rival for TRN's Radio Sport.

MediaWorks, which also owns TV3 and C4, is being bought by Australian private equity company Ironbridge Capital.

The Radio Network is jointly owned by Clear Channel Communications and APN News and Media through the Australian RadioNetwork.

APN also owns newspapers including the Herald.

STATE OF THE AIRWAVES

* Commercial radio in New Zealand is dominated by The Radio Network and MediaWorks.

* After a six-month delay, the nationwide survey of commercial radio listenership begins on Saturday.

* TRN's Viva and MediaWorks' The Breeze are going head to head in a battle for the easy-listening audience.

* On the eve of the survey, TRN is rebranding Viva as Easy Mix.

* The survey could also make or break MediaWorks' RadioLive.