Aer Lingus US partner JetBlue is poised to strike a deal with the Irish carrier's rival Norwegian Air.
JetBlue and Aer Lingus have been partners for almost 12 years, offering connections on each others' flights from Irish and US airports to passengers flying between Europe and North America.
The budget US airline and Norwegian said on Thursday it had taken the first step towards striking a deal that will allow passengers book connecting flights on both carriers on a single ticket.
Troubled Norwegian announced in August it would axe all transatlantic services from Ireland but continues to fly to North America from many European airports.
However, as both Aer Lingus and the Scandinavian company offer cheap flights to North America from cities throughout Europe, they compete with each other.
Norwegian’s proposed deal with JetBlue should aid the Scandinavian airline in attracting US passengers to its services.
Bjorn Kjos, Norwegian's former chief executive, said the company needed to lure US travellers to help ensure its budget transatlantic services were viable. This is the first deal that it has done with a US carrier.
Aer Lingus has been growing its transatlantic business over the last five years. It offers connections between its European and North American flights at Dublin Airport, cashing in on demand for travel between the two continents.
JetBlue has a large network of domestic US routes. These services feed passengers into Aer Lingus flights from the 13 US cities that it currently serves, including New York, Washington, Boston, Los Angeles and San Francisco.
Aer Lingus said on Thursday it had a strong relationship with JetBlue that was mutually beneficial.
“There are no changes to our relationship with JetBlue as a result of this announcement and we look forward to many more years of success working together,” Aer Lingus added.
Earlier this year, JetBlue's chief executive, Robin Hayes, hinted that in the future it could fly between the US and Dublin, putting it in direct competition with Aer Lingus.
Meanwhile, an aviation industry conference heard that the Airbus A321LR, which Aer Lingus intends using to spearhead further transatlantic growth, could usher in an era of low-cost long-haul flying.
Peter Harbison, chairman of Australia-based aviation think tank Capa, highlighted the craft as one of a number that could bring "remarkable change" to the industry.