Fairfax New Zealand and NZME find out on Wednesday morning whether they can merge.
The ruling will follow a year of lobbying and speculation concerning some of the country’s largest media brands, including Stuff and the NZ Herald.
The commission will hold a briefing in Wellington at 8.30am to announce its decision.
If the merger is approved, Fairfax NZ would be folded into NZME, which is listed on the NZX, and Fairfax Australia would become the largest shareholder in the combined business, with a 41 per cent stake.
READ MORE: Your guide to the media merger
The commission said in a draft decision in November that it was minded to reject the merger because it would reduce media diversity.
But Fairfax and NZME responded that the “status quo” in the media industry was unrealistic because of declining advertising and newspaper subscription revenues, and because of competition for the advertising dollar from the likes of Facebook and Google.
Between them Fairfax and NZME own the Stuff and NZ Herald websites, almost all of the country’s major newspapers with the exception of The Otago Daily Times, a raft of community newspapers and magazines, and about half the country’s commercial radio stations, including Newstalk ZB, The Hits and ZM.
They also own own daily-deals site GrabOne, video entertainment site WatchMe and majority stakes in fast-growing community site Neighbourly and internet provider Stuff Fibre.