Irish flag-carrier Aer Lingus is to lease three Boeing 757s to perform transatlantic services from next year.
The carrier disclosed during its first-quarter earnings release that it would damp-lease the aircraft for the routes from early 2014.
Aer Lingus says it reached the agreement on the twinjets, with Irish charter and leasing specialist Air Contractors, in April.
The carrier uses Airbus A330-200s and -300s, configured with 267-322 seats, for its transatlantic services to US gateways.
But the airline says: "We have a number of routes we operate which we can't operate on a year-round basis because the [aircraft] gauge is too high."
Air Contractors declines to confirm that it is supplying the aircraft or to provide further details.
But a source familiar with the situation states that the aircraft would be configured with around 180 seats and that two of the three jets would be stationed at Shannon, with the third at Dublin.
Aer Lingus serves Boston, New York, Chicago and Orlando from Dublin. It also flies from Shannon to Boston and New York, and the use of smaller types from Shannon would potentially allow it to operate more frequently to these cities.
But the airline also envisages opening new routes to North America, using the more flexible fleet, and says that Canadian destinations are "on our radar".