American Airlines and Aer Lingus will this week begin codesharing on flights in the US and Europe—a year after Ireland’s flag-carrier joined the oneworld transatlantic joint venture (JV).

Under the terms of the agreement, Dallas-Fort Worth-based American will place its code on Aer Lingus flights between London Heathrow (LHR) and Dublin (DUB).

American passengers will also be able to book codeshare flights from DUB to Amsterdam (AMS), Birmingham (BHX), London Gatwick (LGW) and Manchester (MAN), as well as from LHR to Belfast City (BHD); Cork (ORK) and Shannon (SNN).

Meanwhile, Aer Lingus will place its code on American-operated flights from Chicago O’Hare (ORD) to Albuquerque (ABQ), Dallas-Fort Worth (DFW), Nashville (BNA), Los Angeles (LAX), Seattle (SEA), San Francisco (SFO), San Jose (SJC) and Tucson (TUS).

Aer Lingus chief strategy and planning officer Reid Moody said the codeshare agreement provides better connectivity between the US and Europe, helping to stimulate leisure, VFR and business traffic.

“Last week’s decision by the Irish government to remove pre-departure COVID-19 test requirements for double-vaccinated passengers is more welcome news,” he added.

Aer Lingus was granted final approval in December 2020 from the US Transportation Department to join the existing oneworld transatlantic JV with American, British Airways, Finnair and Iberia. The decision provides antitrust immunity for the Irish carrier to cooperate within its JV partners on network planning, pricing and sales activities.

The airline currently operates seven routes from Dublin to the US, flying to Boston (BOS), Chicago, New York John F Kennedy (JFK), Orlando (MCO), San Francisco (SFO) and Washington Dulles (IAD). The airline also provides transatlantic service from Manchester to JFK and MCO.