US airline Delta has signalled that it plans to begin flights between Heathrow and the US.
The carrier already operates flights from London Gatwick, Manchester and Edinburgh and now plans to offer flights from Heathrow from March 2008.
Chief operating officer Jim Whitehurst signalled the policy change during a conference call with leading industry analysts.
He said: "We are currently in negotiations for Heathrow slots and should have an announcement soon. Heathrow and two routes to China are the carrier's chief international focus."
Delta would be able to offer the new services when the Open Skies agreement between the EU and the US comes into force next year. Currently, only British Airways, Virgin Atlantic, American Airlines and United Airlines are allowed to operate transatlantic flights from Heathrow.
However, other carriers have already signalled that they plan to offer US flights from the UK's busiest airport when the policy alters in March 2008. This could mean prices on these routes fall for holidaymakers.
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