The newly acquired Liberty Oil wholesale oil business now gives Viva control of 17 regional fuel storage depot, a fleet of more than 50 vehicles and supply to more than 250 dealer owned service stations.

It will operate the existing Liberty Oil service stations in a joint venture with Liberty Oil founders David Goldberg and David Weiland, helping to expand their retail footprint.

It brings the total number of Viva retail sites to 1255 petrol stations, making it the largest single fuel retailer in the country.

However, Mr Wyatt added that these petrol stations will not be rolled into the Coles Express group.

"We see Liberty [and other jointly-owned petrol station chain] Westside as complementary to Coles," he said.

He said there is also the opportunity to open more service stations, "as we now have more confidence in our network."

Viva will officially take control of fuel pump pricing from Coles Express - which the Australian Competition and Consumer Commission said had the highest retail petrol prices in the country - at the end of this week.

It comes after renegotiating the alliance between the two companies, extending their petrol station partnership out to 2029.

Petrol prices hit record highs last year, rising to nearly $1.70 in Sydney and Melbourne.

"We will now be able to improve the competitiveness of pricing for our customers," Mr Wyatt said.

Viva has also announced a collaboration with online auction site Carsales.com, providing fuel discounts to Carsales members.

“Today’s announcement reinforces our commitment to build strategic partnerships. We see fuel discounts as just the start of this new collaboration and we look forward to rolling out further offers in the future,” Viva Energy chief executive Scott Wyatt said.

It is due to launch in the second half of the year.

While the group beat market expecations, it took a massive hit on its refining earnings from its prospectus, recording $124.5 million, down 42.5 per cent or $92.2 million on original expectations, although broadly in line with more recent guidance.

Viva said this was “due to significant weakness in regional refining margins in the later part of the year and a number of external events that impacted operational availability,” the company said.

Deutsche Bank analysts said this weak refining performance was expected.

Rival refiner Caltex also saw lower refining margins as it faced similar tougher global conditions.

UBS analysts said outside of poor refining performance, Viva beat expectations.

"This is a good result overall with Viva exceeding prospectus in controllable areas, excluding refining. We would expect this result to be viewed positively, albeit still no sign of refiner margins normalising, with our expectations of this to happen in the second half of 2019," UBS analysts said.

The company said excluding refining performance, it was ahead of its prospectus underlying earnings by $16 million.

Viva has issued an inaugural, fully franked dividend of 4.8 cents for the second half of 2018, payable 15 April. This represents a payout ratio of 60 per cent of its net profit.

Viva was down 2.5 per cent to $2.34 at 12:15pm in Sydney and Melbourne.