The Maori Internet Society says a Northland iwi selling its broadband network to a private company is like selling off the foreshore and is a big loss for tribal members.
The northern tribe Ngatiwai is quitting the broadband business and selling its high-speed wireless service for an undisclosed sum.
The Northland-based NgatiwaiNET broadband network started 10 years ago, but the Ngatiwai Trust Board Chief Executive Jim Smillie said it had not been profitable.
"It has become increasingly clear that it is not part of Ngatiwai's core business," said Mr Smillie in a press release.
"In recent months we have looked at ways of making sure our customers could keep on getting fast, fairly priced broadband while freeing up Ngatiwai resources for other priorities, and after reviewing several alternatives we decided that Uber Group was best placed to take the NgatiwaiNET wireless network into the future."
Uber provides wireless and fibre broadband services to more than 1,000 people in rural areas throughout Te Tai Tokerau.
Uber coporate services manager Pauline Rose said buying NgatiwaiNET made sense, because it cut out the competition.
"It reduces competition for us in what is a very small market in Northland.
"But it also enables us to expand what we can do here. There are some overlaps, but there are also some areas where we don't have coverage and they do."
Both Uber and NgatiwaiNET refused to say how much the deal was worth.
But Maori Internet Society chair Karaitiana Taiuru was shocked it was happening.
"It's a tool to assist and grow their own tribal members - their health, income, business, education. We need high speed internet. I think the iwi should have reconsidered their options and thought 'it's not a financial profit, but in terms of social responsibility to our tribal members, what are the benefits?"
Uber had promised to honour all NgatiwaiNET plans with current customers.
But it said it would have to upgrade or replace some NgatiwaiNET equipment, which meant there would be outages in April.
The deal takes effect from the first of April.