European regulators have cleared the proposed US Airways-American Airlines merger, on condition that slots be released on the London-Philadelphia route.
In its analysis of the merger the European Commission examined various combinations of transatlantic routes involving non-stop and one-stop connections.
It found that the tie-up would lead to a monopoly on the London-Philadelphia route, as a result of American's transatlantic venture with Oneworld carriers British Airways and Iberia.
The Commission says the carriers have offered commitments to address this situation, including the release of a daily slot pair at London Heathrow and Philadelphia, as well as "far-reaching" feeder arrangements to "induce entry" by a new competitor on this route.
"We are therefore satisfied that the competitive dynamics will be maintained so as to ensure choice and quality of air services for passengers on [the London-Philadelphia connection]," says European competition commissioner Joaquin Almunia.
On other transatlantic routes the merged entity would face competition from "strong" rivals, including the SkyTeam venture between Delta Air Lines, Alitalia and Air France-KLM, says the Commission, as well as the Star Alliance tie-up involving Lufthansa, United Airlines and Air Canada.
Delta's recent investment in Virgin Atlantic would also give the UK carrier additional competitive force, it states.