All Newshub operations are to be shut down and 250 people will lose their jobs. The shutdown includes the company's website.
The last 6pm news bulletin will air on July 5.
Warner Bros Discovery said talks were ongoing with third parties to provide a pared-back news service - such as a 6pm bulletin for the Three channel. However, no deals have been reached yet.
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Head of networks Glen Kyne said Warner Bros Discovery had been clear it would listen to all feedback both internal and external over the five-week consultation period.
"Our door has been open and some conversation have taken place. They're continuing to take place in confidence but there is no deal."
He promised to let staff know immediately if any new deals could be finalised.
He thanked staff for their feedback.
The announcement of the definite shutdown came at an all-staff meeting at a hall close to Newshub's office in Auckland's Eden Terrace on Wednesday morning.
Newshub staff were told by Warner Bros Discovery managers in February it planned to axe the entire news operation.
The newsroom was losing too much money, staff were told.
Since then, it is understood there have been talks between Warner Bros Discovery and a number of media firms, including Stuff, about ways that part of the business could be preserved. It has been suggested that could include the production of a "slimmed-down" news bulletin by a third party.
Meanwhile, TVNZ staff will today hear the fate of its Sunday current affairs show, after the company confirmed on Tuesday it was axing the on-air version of Fair Go, and the Midday and Tonight news programmes.
Spinoff founder Duncan Greive said the changes would be irreversible, and a "tragic" outcome for those affected.