TUI AG (short for Touristik Union International), also known as TUI Group, is an Anglo-German multinational travel and tourism company headquartered in Hannover, Germany.
It is the largest leisure, travel and tourism company in the world, and it owns travel agencies, hotels, airlines, cruise ships and retail stores. The group owns five European airlines – the largest holiday fleet in Europe – and several tour operators based in Europe. It was founded in 1923.
The TUI Group in 2014 operated: 1,600 travel agencies, 150 aircraft, 16 cruise liners, 380 hotels and resorts.
TUI Group owns five European airlines, inherited from TUI Travel, making it the largest tourism group in Europe. The group airlines operate both scheduled and charter flights to more than 150 destinations worldwide departing from more than 60 airports in 9 European countries.
According to en.wikipedia