Waikato fuel supplier Waitomo has taken over two stations in the city — the former Mobils on Cumberland St and Wharf St. They will open in the first week of August.
The company is also opening a new outlet in Christchurch.
The stations will be unmanned and will offer the usual petrol and diesel options.
Waitomo Group managing director Jimmy Ormsby said it would take time for people in the South to become familiar with his company’s brand.
He said Waitomo had been a "market disrupter" in the North Island and it was time for the South Island to enjoy the low prices his outlet would help bring.
"Over the last 10 years, South Island motorists have suffered from price-gouging, paying disproportionately high and unfair prices for their fuel, because of little or no competition in the area.
"Companies have been taking advantage of that lack of competition for a decade, to the detriment of hard-working Kiwis.
"Only in the last six months have we seen prices begin to drop to a fairer level."
Mr Ormsby said his company looked for operations to take over because it was cheaper than building a new site.
"We’ve got quite a strict criteria. We don’t invest willy-nilly.
"The capital to invest in building new greenfield sites just keeps increasing so we’ve got to be very disciplined with how we spend our capital."
The owner of the Mobil stations, Beven O’Callaghan, is going into semi-retirement and a deal was struck between him and Waitomo for two of the four Dunedin Mobil sites.
"We went down and visited with the owners and had a bit of a chat," Mr Ormsby said.
"We got on well. We decided it would be good for us to do some business with them."
Mr O’Callaghan’s company would run a convenience store next to but separate from the two Waitomo fuel stops.
Mr Ormsby said there was a demand for a variety of types of petrol stations providing different options.
"Different customers ... want different things.
"There’s a place in the market for an unmanned no-frills offer ... and then there’s a place in the market for adding additional goods and services to that," Mr Ormsby said.
Waitomo was started in Te Kuiti more than 70 years ago by Desmond Ormsby, Jimmy Ormsby’s grandfather.
At the end of this year it plans to have five stations in the South Island — three in Christchurch and two in Dunedin.
Another self-service petrol station, NPD, is opening its third Dunedin store in Anderson’s Bay Rd at the end of next month.
