International Airlines Group (IAG), is an Anglo-Spanish multinational airline holding company with its registered office in Madrid, Spain and its operational headquarters in London, United Kingdom. It was formed in January 2011 after a merger agreement between British Airways and Iberia, the flag carriers of the United Kingdom and Spain, respectively. It is one of the world's largest airline groups, with 573 aircraft flying to 268 destinations and carrying 113 million passengers each year. It is the third-largest group in Europe and the sixth-largest in the world, based on revenue. Its vision is to be the leading airline group on sustainability.