American Airlines has officially selected Citigroup as its exclusive credit card partner, marking the end of its relationship with Barclays. This new deal is expected to enhance customer benefits through a broader array of options and stronger profit outlook for both companies. With this transition, existing Barclays cardholders will be absorbed into the Citi portfolio, and American Airlines stock has seen a surge in response to the announcement. The partnership, which has spanned nearly four decades, is positioned to reshape AAdvantage miles strategies for travelers, including the integration of Citi’s ThankYou rewards program.