Amex noted that strong demand from "professional services, manufacturing and technology/communications industries" fueled the overall growth. Based on second-quarter bookings by U.S.-based Amex GBT customers and excluding taxes and fees, the data also showed a 5.7 percent decline in client car rental costs. That discrepancy from the growth measured in air and hotel spending "may point to nontraditional disruptors in the [ground transportation] space gaining traction amongst business travelers," according to Amex. Meanwhile, the travel management company reported that its clients during the second quarter booked 87.5 percent of domestic U.S. airline tickets in coach class. For international trips, they booked 55.7 percent in coach class, 1.1 percent in "premium coach," 40.6 percent in business class and 2.6 percent in first class. Get the full story at Business Travel News