Air New Zealand is taking court action against BP and Z Energy over the cut in jet fuel supply after the rupture of Refining NZ's pipeline last year.
The airline has started proceedings against its fuel suppliers in the High Court at Auckland after the disruption which it said cost it millions of dollars as flights were cancelled or diverted to other airports to refuel.
While Air New Zealand was hardest hit, other airlines also had to take costly action to keep flying as fuel supplies were cut at the country's busiest airport.
A Z Energy spokeswoman said her company had received a statement of claim from Air New Zealand for about $4.3 million. Z would be defending the claim and, as the matter was before the court, she could no comment further.
A BP spokeswoman had a similar response.
''BP strongly denies Air New Zealand's claim and will be defending the proceedings,'' she said.
''As this matter is now before the court, it is not appropriate to comment further at this time.''
Air New Zealand is not commenting on the preliminary proceedings which started today.
It could be next year before the case is heard.
In September the 170km refinery-to-Auckland pipeline on farmland near Marsden Point was ruptured.
Airlines were hardest hit as the pipeline carries nearly all of Auckland's aviation fuel.
Flights were disrupted or cancelled for about 10 days until the pipeline was repaired.
Air New Zealand chief executive Christopher Luxon said after the cut the airline would look at ways of recouping its losses.
Refining NZ - which is part-owned by the oil companies at the centre of the court action - runs the pipeline and took an $8m hit to its profit.
Auckland Airport last year estimated the impact of the loss of business was in the "low hundreds of thousands of dollars" and would be covered by business interruption insurance.
During the crisis some other airlines had to divert to other airports or tanker in fuel to Auckland in other aircraft.
The Board of Airline Representatives today said each individual airline would make their own decision on any legal action based on their commercial contracts with their suppliers.
Energy and Resources Minister Megan Woods has said there would be an inquiry into the pipeline failure and into ways of making fuel supply to the airport more resilient.
Two digger drivers were interviewed about working at the Ruakaka site when Refining NZ's Auckland fuel products pipeline was ruptured, but neither could recall working near the pipeline.
Northland Regional Council said early this year the fuel leak - estimated at 124 cubic metres - was a breach of the Resource Management Act but the council "does not have a case for prosecution".