US Airways' chairman Stephen Wolf caused consternation in Whitehall by thanking "key public officials" for it winning the right to start operating services to Charlotte, Virginia.
Mr Wolf praised the entireClinton administration, singling out Vice President Al Gore, Transportation Secretary Rodney Slater and Secretary of State Madeleine Albright for providing "vigilant and steady leadership".
One source said Mr Gore had held talks at "the highest level" while on a visit to the UK. But the Department for the Environment, Transport and the Regions insisted that ministers had played no part in the decision.
The issues of slots for US Airways and Continental to fly to, respectively, Charlotte in Virginia and Cleveland in Ohio, led to the breakdown of preliminary talks between the two governments over liberalising air travel.
The talks ended without resolution after Britain told the US that under European Union law allocation of runway slots was not in the British government's gift, but was a matter for the industry's own slot scheduling process. Slots are allocated by an independent committee, Airport Co-ordination Limited, and the implication that the decision resulted from White House pressure could upset rival airlines and the European Commission.
Mr Wolf said he was delighted that US Airways could offer competition on that route. But he added: "This has been a team effort at all levels of government - federal, state and local - in support of the principle of competition in international aviation."
But a DETR spokesman said: "The British Government had no direct involvement in the Gatwick situation. It shows the slot system works for US carriers if they are persistent."