Treasurer Andrew Barr announced on Wednesday that the Suncorp-owned brands AAMI, GIO and Australian Pensioners Insurance Agency had been granted licences to offer compulsory third party insurance in the territory.

Submissions from the three brands on proposed premiums would be considered by the CTP regulator after July 1.

NRMA Insurance charges $579 for CTP cover on a class 1 private vehicle.ACT third party premiums are among the highest in Australia.

Mr Barr said a combination of more competition in the insurance market and better driving by motorists would leave ACT drivers in a much better position.

"I think we have the best roads in Australia, we have some of the best infrastructure in Australia," he said.

"So there’s no reason for the ACT to have high CTP premiums. If we can improve our road safety performance and our competition in the market place, then we should have some of the lowest premiums in the country."

GIO executive general manager Chris McHugh said competition would enable drivers to get better deals. "We believe we can offer something in terms of both service and value," he said. "GIO believes in rewarding good drivers. We will be offering rebates to good drivers who choose GIO for CTP cover."

Successive ACT governments have failed to lure new entrants into the CTP market.

Mr Barr was careful not to promise an immediate fall in the cost of premiums as a result of Suncorp’s decision but said financial incentives for safe driving could benefit many motorists.

Vehicle registration renewal notices issued after new premiums are approved would include information about the range of providers.

Shadow treasurer Brendan Smyth welcomed the entry of Suncorp into the market. He said more competition had been achieved without the need for the changes to personal injury lawsthat had been championed by the government.

"I’d be saying to the people of Canberra, ‘You’ve now got some options, shop around, make sure you get a good deal because hopefully that’s what competition brings to the market," Mr Smyth said.

"But just remember the government wanted to give away your rights to access common law should you have a significant accident. We didn’t; we protected your rights."

The ACT Assembly last year knocked back reforms to personal injury laws that the government had hoped would help attract more CTP providers to the market and limit premium rises.

Mr Barr said the government was still committed to reforming personal injury laws. "Early medical intervention is seen as very important – that is part of our policy approach," he said.