Motorists will soon have access to the same petrol price information as retailers, under a deal brokered by the competition watchdog.

The Australian Competition and Consumer Commission (ACCC) has reached agreement with petrol price information service Informed Sources and four major petrol retailers to make almost real-time data available to motorists.

Currently, the retailers have exclusive access to information about petrol price moves within 15-30 minutes of when they occur through Informed Sources.

Under the deal, Informed Sources will make the same information available to consumers for free and to third parties on commercial terms.

The ACCC's chairman Rod Sims told ABC News that this will facilitate improved competition amongst petrol retailers.

"Consumers will have the information to shop and get the best deal, that will improve competition on the ground," he argued.

"Secondly, ourselves and motoring organisations and others will be able to see exactly what's going on, who's leading prices up, who's leading prices down."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 3 minutes 21 seconds 3 m 21 s Petrol price data made freely available to consumers ( Lucy Carter ) Download 6.2 MB

However, independent South Australian Senator Nick Xenophon has criticised the ACCC for its lawsuit against Informed Sources, arguing it could have come to such an arrangement without launching expensive court action.

"The ACCC needs to refund Informed Sources the legal fees it needed to fork out to defend this ill-conceived prosecution," he said in a statement.

"The whole prosecution has cost millions and it could have been avoided with common-sense discussions, which would have meant consumers would have got the benefit of this real-time information years earlier."

Mr Xenophon does not explain in his statement why Informed Sources had not, up to this point, made near real-time data available to consumers of its own volition when it has been selling such information to fuel companies for many years.

Mr Sims said the regulator and motoring groups have been asking for this information for years.

"They [Informed Sources] must also give the information to other third parties on reasonable terms, and those third parties could be other information providers, by that I mean really app providers, but also regulators, consumer organisations and, most importantly, the motoring organisations - they've been wanting this information for some time," he added.

Competition in the retail fuel market has been under the spotlight recently, with gross profit margins at their highest levels on record.

The ACCC had already reached a settlement with Coles Express where that retailer had agreed to stop using the Informed Sources service once its current contract expired next year.

This agreement covers the other major fuel retailers: BP, Caltex, Woolworths and 7-Eleven.

The deal is a settlement between the ACCC, Informed Sources and the retailers to end a lawsuit that the regulator was pursuing in the Federal Court under the collusion and cartel provisions of the Competition and Consumer Act.

Parties have agreed to pay their own legal costs under the settlement.