AmEx’s shares fell 1.4 percent to $79.80 after the bell on Thursday. Revenue from international operations, net of interest expense, fell 8 percent to $1.24 billion in the quarter ended March 31, accounting for about 16 percent of AmEx’s total revenue. Total revenue, net of interest expense, fell 2.7 percent to $7.95 billion. AmEx also said the termination of several co-branded relationships, including that with Costco Wholesale Corp in Canada last year, hurt revenue.