Despite the fact the U.S. Transportation Department approved a potential code-sharing agreement between United Airlines and BMI British Midland in April, talks between national governments have yet to yield the “open skies” agreement necessary for implementation.

On Oct. 3, the U.S. government extended its conditional approval of anti-trust immunity for the alliance to the end of the year. However, British and European regulators have been at odds on widening access to London’s Heathrow Airport, and few see any signs of a resolution before the end of the year.

At present, the British government only allows two U.S. airlines, American and United, to offer direct transatlantic service from Heathrow.