the differing sizes of Heathrow's and Gatwick's catchment areas are far less significant for non-premium travel as many people are prepared to travel to an airport outside their catchment area to take advantage of a cheaper flight. However, the growing presence of aggressive low-cost, "no frills" airlines at Luton and Stansted respectively in recent years has somewhat diminished Heathrow's advantage in terms of its catchment area, as far as short to medium haul flights are concerned. Like Heathrow, these airports are located north of the Thames where most of the people in London and the Southeast live and their catchment areas, particularly Luton's, overlap with it. BA's failed attempt at a "virtual" merger with American Airlines During the summer of 1996 BA announced that it was planning to enter into a new code- and revenue- as well as profit-sharing alliance with American Airlines. The planned alliance was the most ambitious and far-reaching commercial airline alliance attempted at the time. It was also dependent on being granted anti-trust immunity by the British Government and the United States Department of Justice as well as the European Commission's Competition Directorate. This mega alliance was meant to replace the much more limited code-share agreement BA had with US Airways since the beginning of 1993, which was not dependent on anti-trust immunity. The new alliance envisaged merging the transatlantic operations of both airlines by combining all their commercial activities into a joint company, thus making it a "virtual" merger. One of the new alliance's most outstanding features was a plan for an hourly shuttle service between London Heathrow and New York John F Kennedy, the world's busiest and most profitable intercontinental air route. This meant that BA, which at the time only controlled about 38% of all take-off and landing slots at Heathrow, needed to secure additional prime time slots at Heathrow in order to be able to launch the hourly JFK shuttle. In those days secondary slot trading, where airlines buy and sell take-off and landing slots at congested airports, was still in its infancy and there was uncertainty concerning the legality of this activity. In anticipation of gaining all necessary approvals for the proposed alliance — including anti-trust immunity, BA decided to reserve the required slots at Heathrow by moving all long-haul services to East, Central and Southern Africa (other than those to South Africa itself) as well as to Latin America to