The flag carrier’s five-times weekly Heathrow-Portland service will get under way on 1 June 2020, flying from Terminal 5.

It increases BA’s US route network from London to 27 and grows daily UK-US services to 86 when combined with those operated by transatlantic joint business partner American Airlines.

Portland flights will depart on Mondays, Wednesdays, Fridays, Saturdays and Sundays, operated by Boeing 787 Dreamliner aircraft.

Return fares lead in from £459 in World Traveller; £758 in World Traveller Plus; and £1,399 in Club World. Flight time is around 10 hours 20 minutes.

Outbound flights will depart Heathrow at 3.05pm, arriving Portland 4.55pm. Returns depart Portland at 6.45pm, arriving Heathrow 12.10pm.

Heathrow-Portland is one of eight new Europe-North America routes launched by Atlantic joint business partners BA, American Airlines, Finnair and Iberia for next summer.

Neil Chernoff, BA director of networks and alliances, said: “Portland will be a fantastic addition to our route map. As a major technology and innovation hub, the city is drawing ever-increasing numbers of international visitors.

“Since 2015, we’ve launched routes to Pittsburgh, Charleston, Nashville, New Orleans and San Jose, and this is key to our joint business strategy which is growing across North America.

“We’re confident the route will be warmly welcomed by both business and leisure travellers.”