Etihad, the Abu Dhabi-based airline, and Kingfisher Airlines of India are negotiating deals to gain access to more take-off and landing slots at London Heathrow.

Long-haul carriers are taking over more of the prized slots at Heathrow from short-haul services as widebody jets replace smaller aircraft and some incumbent carriers seek to cash in on the slot trade. The trend is allowing passenger numbers at Europe’s most congested airport to grow without an increase in flights.