Under the agreement, JetBlue will place its B6 code on four Aer Lingus’ transatlantic routes: from Dublin and Shannon to both New York JFK and Boston Logan International.

JetBlue also plans to add its code to “select” Aer Lingus routes beyond Ireland in the “near future”.

Lynne Embleton, chief executive of Aer Lingus, said: “Our relationship with JetBlue is long-standing and valued. All at Aer Lingus are looking forward to extending a warm Irish welcome to more JetBlue customers.

“These customers can now travel seamlessly to Dublin and Shannon airports as we continue to connect friends and families, businesses and colleagues from the US and Europe.”

Joanna Geraghty, chief operating officer at JetBlue, added: “More than 13 years after Aer Lingus became our very first international airline partner our relationship continues to strengthen in ways that bring more benefits customers on both sides of the Atlantic.”

JetBlue launched its first transatlantic flights from the UK to New York earlier this year with services from both Heathrow and Gatwick.