Answer: Euroleague
Turkish Airlines Euroleague, commonly known as the Euroleague, is the highest level tier and most important professional club basketball competition in Europe, with teams from up to 18 different countries, members of FIBA Europe. For sponsorship reasons, for five seasons starting with 2010-2011, it is named Turkish Airlines Euroleague. The competition is operated by ULEB, a Europe-wide consortium of leading professional basketball leagues.
