The state-owned broadcaster said it now expected an underlying loss of between $28 million and $33m in the 2024 financial year.
It said on top of the underlying loss, TVNZ's full-year result would include a significant non-cash write-down as the value of its assets would be affected by future earnings forecasts.
It said traditional television advertising was down nearly 16 percent from last year, and only partially offset by digital revenue, despite revenue growth on its TVNZ+ streaming platform.
"We have made significant strides in our path to being a digital-first broadcaster over the past six months, however, as a fully commercially funded organisation, we are exposed to the ad market," chief executive Jodi O'Donnell said.
"Since we announced our interim position, the advertising downturn driven by recessionary conditions and structural market change has deepened. TVNZ's revenue position as a result has deteriorated, despite a continued focus on cost saving initiatives," O'Donnell said.
In its half-year results announced in March, TVNZ reported a bottom line loss of $16.8m, and an underlying loss of $4.6m.
Following the results, TVNZ announced 68 jobs would be cut, including its Sunday and Fair Go programmes.
However, the Employment Court ruled it had failed to consult with staff before cancelling the programmes and cutting jobs.
O'Donnell said despite the tougher results, it was not looking for a government handout.
"While we strongly support regulatory and legislative change to encourage a fairer playing field and fit-for-purpose operating environment, we are not seeking financial support from the Crown," O'Donnell said.
She said TVNZ's balance sheet was "robust".
In response to the tougher television advertising market, TVNZ said it would be accelerating its digital changes.
"We will continue to invest aggressively in a digital future to build online audience and revenue scale, and to secure a profitable and sustainable future for the business," O'Donnell said.
