Amex, Costco To End Partnership March 31, 2016

American Express Company said Thursday it will end its U.S. co-branding and merchant acceptance agreement with Costco Wholesale Corp. on March 31, 2016. Amex Chief Executive Kenneth Chenault said the partners were unable to reach terms "that would have made economic sense for our company and shareholders". Amex shares were not yet active in premarket trade, but are down 6% in the last three months, while the Dow Jones Industrial Average has gained 1.4%.