Lufthansa plans to use Jet-Blue as its feeder partner in New York by linking booking systems and frequent-flyer programmes.
The German airline said the link-up with the US carrier, in which Lufthansa took a 19 per cent stake at the end of last year, was aimed at creating a quasi-hub at JFK airport.
It said the move would add to the benefits of owning BMI British Midland, the UK airline in which Lufthansa holds a stake of just under 30 per cent and in which it has an option to buy a majority stake from December.
The German carrier has long wanted to challenge its rival British Airways on the lucrative routes between London Heathrow and the US.