"We are seeing a more positive environment for air travel demand, based on rising business confidence," IATA chief Tony Tyler said.
Rising export orders and improvements in key emerging markets such as China had also contributed to the improvement, he said in a statement.
Despite the continuing strong demand, September nonetheless marked a slight slowdown from August, when global airline traffic grew by 6.8 percent, enabling the industry to match an all-time record of 83.4 percent of seats filled.
Tyler remained optimistic.
"The strong growth of recent months, coupled with the continuing improvements in air travel demand in September, suggests that there could be a further acceleration in air travel growth before the end of the year," he said.
Traffic on international routes was up 5.7 percent in September, with Middle East carriers showing the strongest year-on-year traffic growth of 10.4 percent.
Asia-Pacific carriers meanwhile registered 8.5 percent growth, IATA said, adding that improvements in the Chinese and Japanese economy in the third quarter appeared to have helped ease the downward pressure on growth seen in recent months.
