TVNZ says if the Sky-Vodafone merger goes ahead, more people will have to pay for premium content that is supposed to be free-to-air.

It has made a submission to the Commerce Commission against the deal, along with Spark, 2Degrees, Trustpower and Internet NZ.

READ MORE: Sports fans will suffer if Vodafone-Sky merger goes ahead, says Spark

TVNZ CEO Kevin Kenrick said Sky's acquisition of TV channel Prime has allowed the company to purchase free-to-air coverage, and then charge viewers for it.

He said the merger will make it easier for Sky to acquire more free-to-air rights, then remove them from the marketplace by putting them behind pay walls.

"Our concern is that market power would then be extended across subscription video on demand, transactional video on demand, pay-per-view, all those things," he said.

"TVNZ covered the Beijing Olympics in 2008, there were 800 hours of coverage that were available free-to-view - Prime has only made 240 hours of Rio available, and most of that's been delayed rather than live."

The merger announced in June is worth almost $3.5 billion.