The Herald understands Petrie was told on Thursday about the move, which is part of a Covid-19 restructure the company announced on June 15.
On June 20, the Weekend Herald reported that Petrie and Dallow were having to apply for the same role as sole newsreader of the weekday 6pm bulletin. TVNZ had earlier confirmed it would reduce 70 to 90 roles to recover a 30 per cent loss in revenue during the Covid-19 lockdown.
TVNZ tonight said it had no comment to make. Petrie did not respond to Herald requests for comment.
Petrie and Dallow have co-anchored the 6pm bulletin since 2006, after taking over from Judy Bailey, who had been the sole news reader since 2004.
Petrie has had time off over the past two weeks, with TVNZ confirming this week she has been on a school holiday break with her family.
She presented Thursday and Friday's 6pm bulletin this week.
Dallow has also been away this week and it is not clear if TVNZ bosses have been able to sit down with him.
Different news readers have been filling in, including Jack Tame, John Campbell and Melissa Stokes.
On Thursday, Petrie posted a group photo to her Instagram of some of the TVNZ presenting team together formally smiling for the camera.
"Sneaking a team pic between the ad break," the caption read.
Earlier in the week she also posted a photo of a bunch of flowers from her "gal friends" and "the gift of a giant Lego ship" from her 10-year-old son.
Earlier this week, TVNZ told the Herald it had nothing further to add regarding finalising job losses.
In late June, Petrie denied to the Herald any decision had been conveyed from TVNZ management, saying "it's all very confidential".
However, when announcing the job losses, TVNZ chief executive Kevin Kenrick said the company "expects to confirm the new business structure by early July".
Kenrick said TVNZ was trying to recover from a 30 per cent revenue drop influenced by Covid-19's impact on the advertising market.
The broadcaster is trying to save $10 million in this process.
The Herald is aware of other journalists in the TVNZ newsroom on three-figure salaries who were told in early June they no longer have a job.
Final consultation meetings with staff and management were reportedly occurring over the past two weeks.
There are also murmurings that TVNZ staff are particularly unhappy with how the consultation process has been dealt with, and that certain departments within the newsroom are visibly despondent.
The Herald understands almost half of video archive staff in the newsroom are being cut.
Award-winning TVNZ reporter Janet McIntrye also resigned from the Sunday programme after 27 years - but it is understood the decision was not directly related to the restructure.
On June 29, McIntyre appeared in the Auckland District Court.
It is understood the decision to reduce to just one permanent 6pm news reader crystallised for management during lockdown when there was only a single week-night news anchor.
During lockdown the newsroom had been separated into two teams, who entered the TVNZ Auckland bureau in Victoria St in the CBD on alternating weeks.
At the weekend, the 1 News 6pm bulletin only had one news anchor.
In March, the Herald reported that of TVNZ's top-20 highest-paid presenters between 2017-19, the average man earned $254,510 a year. Women in the group were paid $210,597.
On June 26, as head of news and current affairs, John Gillespie, finished his last day at the company after 23 years.
Gillespie announced his resignation to TVNZ staff on February 26, independent of the current consultation process.
In a 2017 round of TVNZ redundancies, weekend news reader Bernadine Oliver-Kerby lost her job at the state broadcaster after 25 years.
In 2000, news reader John Hawkesby received a $6.5m payout after he was made redundant by TVNZ.
The Covid-19 economic slump has led to a massive downturn in advertising revenue for all New Zealand media outlets.
On June 12, MediaWorks slumped to a $25.14m loss, casting "significant doubt" on the company's ability to continue.
On April 4, TVNZ's Kenrick informed staff of the company's strategy to "preserve cash" and its fresh eligibility for the Government's wage subsidy.
In April, NZME, which owns the NZ Herald, announced 200 job losses and asked staff on a salary of more than $50,000 per year take a 15 per cent pay cut for 12 weeks.
In April, Stuff also asked its employees on more than $50,000 to take a voluntary 15 per cent pay cut, and their senior executives to take a 25 per cent cut.
