US Airways has been awarded the landing rights to start daily flights from Heathrow.
It has decided to launch a new daily service from Heathrow to its hub in Charlotte, North Carolina, in March.
Flights will continue on to Miami, offering a one-stop service to Florida from London.
The airline says the new route will complement its daily flights to Philadelphia from Heathrow.
The landing rights became available when oneworld carriers had to give up some of their collective slots in order to win regulatory approval for a transatlantic joint venture.
