LONDON – The world’s top 5 most valuable airline brands logged brand value growths of at least 11%, according to a new report by Brand Finance, the leading brand valuation consultancy. American brand Delta (brand value up 21% to USD10.8 billion) retained its top position as the world’s most valuable airline brand for the sixth consecutive year. Similarly, other American brands, American Airlines (brand value up 21% to USD10.2 billion), United Airlines (brand value up 11% to USD8.7 billion) and...