Media executives from Nine say they remain "very confident" in their Olympics coverage, despite hundreds of newspaper journalists launching a five-day strike on Friday.

Staff from The Age, Sydney Morning Herald, The Australian Financial Review, Brisbane Times, and Watoday started rallies outside of their offices in Melbourne, Sydney, Brisbane and Perth on Friday morning.

They plan to strike for five days after rejecting a revised pay offer from Nine on Thursday.

In an email sent to staff and seen by the ABC, Nine CEO Mike Sneesby said management was "profoundly disappointed" in the action but had been preparing for it.

"Tory [Maguire] and I remain very confident our newspapers will deliver comprehensive, world-class coverage of the Olympics across our online and print assets," he said.

Staff have been in negotiations for months with Nine Entertainment executives to secure a pay deal that is slightly higher than inflation, which unions members say is necessary after they agreed to a pay freeze during the COVID pandemic.

An offer of 3.5 per cent in the first year, 4 per cent in the second year and 3 per cent in the third year was rejected by the union yesterday.

Members are also fighting for a commitment to improving diversity, safeguards around the use of artificial intelligence, and a better deal for freelancers that includes paying superannuation and a transparent pay system.

In Melbourne, about 100 editorial staff from The Age have walked off the job.

Staff holding placards and wearing t-shirts printed with Don't Torch Journalism walked out as a group from their headquarters in Docklands.

State political reporter at The Age and Media, Arts and Entertainment Alliance member Broede Carmody said journalists did not want to walk out today but were forced to show how serious they were about a better enterprise bargaining agreement.

Nick McKenzie, an investigative journalist from The Age and The Sydney Morning Herald, told ABC Radio Melbourne staff were asking for a fair go from management.

"It's a tough job, it's a difficult job, and what they're asking for is some support from management to do that journalism."

He said some reporters would be on strike from Paris, and it would affect the newspapers' coverage of the Olympics.

Nine says 'disappointing' strike won't harm coverage

A Nine spokesperson said while the industrial action was "disappointing", the production of its publishing mastheads would not be affected.

"Nine recognises the rights of unions to take industrial action but believe that a return to the negotiating table is the best way to progress the EBA," the spokesperson said.

"With our new and improved proposal representing a fair and reasonable offer for our people, we remain open to resuming good faith negotiations at the earliest opportunity."

"We can confirm comprehensive plans are in place to ensure the production and distribution of Nine Publishing mastheads will not be impacted and our readers will continue to have access to unrivalled coverage of the Paris Olympics."

Nine is the official Olympics broadcaster, and 18 staffers have travelled to Paris as part of planned coverage. The strike will not affect television coverage.

MEAA director Michelle Rae said the decision to strike came after 90 redundancies were announced across the publications due to the end of a funding deal with Facebook parent company Meta.

The deal was struck three years ago with the Coalition government under the News Media Bargaining Code to pay publishers for using news stories on its new tab.

But earlier this year, Meta ended its agreement with a raft of Australian news organisations, including the ABC.

Melbourne staff locked out of office

On Friday afternoon, union members in Melbourne found out they had been locked out of Nine newspapers headquarters.

An email to members seen by the ABC told staff on strike their security passes had been deactivated and would no longer let them into the building.

Members have also been booted from their work Slack account and some staff cannot access their work email account.

Journalist and co-chair of The Age house committee Bianca Hall said staff had gone to a local pub for a break and would continue action on Monday.

"We have 30 days of protected action and a range of options within those 30 days including [making statements on] social media and public statements."