Local casino operators say they could miss out on a licence to operate online, as they prepare to square up against large offshore operators with deep pockets.
The government has offered more information about how it proposes to regulate online gambling.
It will issue 15 licenses for online casino operators, but they will be competed for at auction.
National campaigned on making offshore online casino operators pay gaming duty of 12 percent on gross betting revenue.
It predicted closing the loophole would bring in an average of $179 million a year over four years, or $719m in total.
There are about twice that number currently operating in New Zealand.
Local casinos say that could create a situation where they are beaten to the licenses by foreign operations without social obligations to this country.
Local casinos concerns over upcoming online gambling changes
Jason Walbridge, SkyCity chief executive, told Nine to Noon he welcomed a competitive market. But he said if the aim was to protect jobs and grow the economy, there needed to be local licensed operators in online gambling.
"We're a trusted brand in New Zealand, Kiwis know who we are."
He said he was waiting for more information in the coming months but was concerned that the licenses could simply go to the highest bidder.
"These offshore operators are enormous companies with large balance sheets and lots of money in their bank accounts. They are able to bid significant sums for these licenses. That's why we think it's important the government take into account the need to have New Zealand-licensed operators."
He said local firms were best placed to protect New Zealanders.
Those operating overseas would not necessarily be as focused on host responsibility or anti-money laundering rules, he said.
He said the fact the government was limiting the licenses to 15 was a good thing, and he had suggested fewer. More operators would mean a more competitive marketing and more advertising, he said.
"None of us want to wake up and see gambling ads on every device we log on to."
Christchurch Casino chief executive Brett Anderson said he did not think the current plan took into consideration the long-term benefit to New Zealand.
While local casinos were also in business to make profit, he said, their employees worked in the community. "The larger [the] number of entities we have the more challenging it is to ensure we are minimising harm."
New Zealand-based operations would have a "door to knock on" for regulators, and a social licence they wanted to maintain.