American Airlines made this announcement:
Traveling between the United States and Ireland, also known as the Emerald Isle, will be simple, easy and more convenient for customers as American Airlines and Aer Lingus launch their codeshare agreement this week.
To increase connectivity between the U.S and Europe for customers, American will place its code on Aer Lingus flights between London Heathrow (LHR) and Dublin (DUB). Customers can also book codeshare flights on Aer Lingus from DUB to Amsterdam (AMS); Birmingham, UK (BHX); London Gatwick (LGW) and Manchester, UK (MAN); and from LHR to Belfast City, Northern Ireland (BHD); Cork, Ireland (ORK) and Shannon, Ireland (SNN).
Additionally, customers traveling with Aer Lingus will now be able to book codeshare travel on American Airlines flights from Chicago O’Hare (ORD) to Albuquerque, New Mexico, (ABQ); Nashville, Tennessee (BNA); Dallas-Fort Worth (DFW); Los Angeles (LAX); Seattle (SEA); San Francisco (SFO); San Jose, California (SJC) and Tucson, Arizona (TUS).
Further expansion of the codeshare is also planned in the near future.
Aer Lingus joined the Atlantic Joint Business (AJB) between American, British Airways, Iberia and Finnair last year. The AJB has brought significant benefits, such as lower fares and easier journeys to more destinations with better aligned schedules and frequencies, to millions of passengers since its launch in 2010.