Albury motorists are paying up to 11c less per litre for their unleaded petrol than Canberra motorists.

Associate professor in business law at the University of NSW, Frank Zumbo, said Albury's average price for unleaded petrol was consistently lower than Canberra's because it had more independent operators.

Lack of competition among petrol retailers will continue to be felt in Canberra.

CommSec, which is tipping a 2-3c rise in pump prices over the next fortnight, says potential threats to oil supplies in the Middle East and improving economic conditions in the US are key drivers behind the surge in global oil prices.

Mr Zumbo said there was an onus on the government to intervene. ''When you have the sector heavily dominated by the oil companies and Coles and Woolworths, you have a market failure,'' he said.

ACT Minister for Economic Development Andrew Barr said attempts to attract more independents by making sites available had been tried over the past 15 years without much success.

''The small number of independent operators in Canberra is due largely to the operation of the wholesale petrol market. This is outside the control of the ACT government,'' Mr Barr said.

He said the government would not broaden the supermarket competition policy, which sidelines Woolworths and Coles on specific sites to give independent operators a chance of buying them.

Mr Barr said sites were not necessarily earmarked for service stations. ''It is up to petrol retailers to identify sites and make an application for a petrol station under normal [processes].''

According to Environment and Sustainable Development ACT there are 54 service stations in the territory, eight fewer than in 2007.

Mr Barr said advice had been sought from the Australian Competition and Consumer Commission on whether the ACT had enough service stations, but ultimately it was a matter for the market.

Motor Trades Association ACT executive director Mick Gentleman said service stations were closing at a time of rising population and an increase in the number of cars in Canberra. He said if you deducted the number of people under the driving age from a population of 360,000, the remaining number accounted for almost one registered vehicle per head of population.

The independent Williamsdale Service Station, located south of Canberra, will close at the end of the month as owner Bob Moore, whose father began the business in 1961, is in ill-health. The independent Kingston service station owner in Eyre Street, Robert Holmes, cannot say how long he will stay in business, as the land adjoining a car park is awaiting redevelopment. Latham service station has been converted to units and Lyons service station is being converted to units. Applications have been approved to change Waramanga service station to units and Watson service station to commercial uses.