Oct 19 (Reuters) - Credit card issuer American Express Co reported its lowest quarterly revenue in more than five years on Wednesday as it struggled to make up for the loss of its contract with Costco Wholesale Corp.
Total revenue, net of interest expense, fell 5 percent to $7.77 billion in the three months ended Sept. 30 - the first quarter with no revenue from the Costco partnership.
Net income attributable to common shareholders fell about 10 percent to $1.11 billion. On a per share basis, AmEx earned $1.20.
Costco co-branded portfolio accounted for about 8 percent of the spending on AmEx cards in 2015.
(Reporting By Sudarshan Varadhan in Bengaluru; Editing by Don Sebastian)