It is headquartered in London , England, near its main hub at Heathrow Airport. The airline is the second largest UK-based carrier, based on fleet size and passengers carried, behind easyJet. IAG is the world's third-largest airline group in terms of annual revenue and the second-largest in Europe. On 31 March , all four companies were merged to form British Airways. However, it marked as its centenary based on predecessor companies. It is a founding member of the Oneworld airline alliance, along with American Airlines , the now-defunct Canadian Airlines , Cathay Pacific , and Qantas.
The alliance has since grown to become the third-largest, after SkyTeam and Star Alliance. The chairman of BOAC, Miles Thomas, was in favour of a merger as a potential solution to this disagreement and had backing for the idea from the Chancellor of the Exchequer at the time, Rab Butler.
However, opposition from the Treasury blocked the proposal. Following two years of fierce competition with British Caledonian , the second-largest airline in the United Kingdom at the time, the Government changed its aviation policy in so that the two carriers would no longer compete on long-haul routes.
British Airways and Air France operated the supersonic Concorde airliner, and the world's first supersonic passenger service flew on 21 January from Heathrow Airport to Bahrain International Airport.
Service to Singapore was established in co-operation with Singapore Airlines as a continuation of the flight to Bahrain. In the airline was instructed to prepare for privatisation by the Conservative Thatcher government. While many other large airlines struggled, King was credited with transforming British Airways into one of the most profitable air carriers in the world. The intense rivalry between British Airways and Virgin Atlantic culminated in the former being sued for libel in , arising from claims and counterclaims over a "dirty tricks" campaign against Virgin.
