American Airlines, the world’s largest carrier based on passenger traffic, has filed a statement with the U.S. Securities and Exchange Commission advising that it expects new co-branded card partnerships with Citi and Barclaycard US to generate a $1.55-billion increase in pretax earnings through 2018. Even though profit margins are not what they once were, co-branded airline portfolios are valued for their stability, targeted distribution capacity, the loyalty of cardholders, and their low credit risk. The American Airlines portfolio was the last major airline co-branded card business on ...