Last year, several high-profile presenters departed, including weather presenter Karen Olsen, weekend newsreader Bernadine Oliver-Kerby, Fair Go's Gordon Harcourt and Breakfast hosts Rawdon Christie and Nadine Chalmers-Ross.
Staff were warned the company is forecast to become unprofitable within two years unless major changes are made.
In August, TVNZ reported a net profit after tax of $12.7m for the financial year ending June 2016, down from $28.1m the previous year.
Chief executive Kevin Kenrick confirmed in December that staff had been spoken to about the need to create "a more sustainable future" for TVNZ.
In a statement, he said: "The current free-to-air model is not sustainable in the long term... This is a [free-to-air] industry wide challenge - TV Works [TV3] and Prime do not make money but are subsidised by their parent company's radio and pay TV operations."
TV audience is fragmenting as an increasing number of people use on-demand streaming services such as Netflix and Lightbox.
TVNZ net profit after tax:
2016
: $12.7m
2015
: $28.1m
2014
: $14.2m
2013
: $14.4m
2012
: $14.2m