FILE PHOTO: The Citigroup Inc (Citi) logo is seen at the SIBOS banking and financial conference in Toronto, Ontario, Canada October 19, 2017. REUTERS/Chris Helgren

(Reuters) - Citigroup Inc said on Monday it was planning to offer a high-interest online savings account early next year to users of its American Airlines co-branded credit card.

The savings account, Citi Miles Ahead savings account, will offer up to 50,000 miles as a sign-on bonus and a 25% boost on miles earned through the card, the bank said in a statement.

The digital service will only be available in areas where the bank does not have physical branches.

American Airlines did not immediately respond to Reuters’ request for comment.