IAG, formed in 2011 by the merger of traditional flag-carriers British Airways and Iberia, has under CEO Willie Walsh recently embraced budget flying, buying Spanish budget airline Vueling in 2015 and setting up its own long-haul low-cost carrier last year. Norwegian meanwhile has been the trailblazer of low-cost long-haul flying in Europe, undercutting rivals on trans-Atlantic ticket prices, but expanding at a rate which has left it under pressure to control costs and shore up its balance sheet. Last month it raised $168 million in a share sale after warning of a larger than expected first-quarter loss.