Costco shoppers who have been limited for years to American Express credit cards may be able to pluck a new option from their wallets or purses next year when an exclusivity deal between the two companies expires. American Express said Thursday that it hasn't been able to come to an agreement with Costco on renewal terms. The current agreement covers U.S. stores and dates back 16 years. It will end March 31, 2016.

American Express executives said in an emailed statement that revenue growth will be affected. Costco is the world's second-largest retailer by revenue, according to the National Retail Federation.

American Express said that Costco pays a significantly lower rate than the overall average it imposes on other retailers as part of the agreement.

- Associated Press

That arrangement gave the credit card company exclusivity for almost two decades, though debit cards and cash are also accepted.

- Associated Press