Kansai International Airport, Japan's second-busiest international gateway, had its biggest monthly drop in passengers since 2003 in June.

The airport had an average of 28,600 passengers a day last month, a 34 percent drop compared with a year earlier, its operator said Wednesday. It was the biggest decline since June 2003.

The airport, which cost ¥1.46 trillion to build, is struggling to retain airlines as tumbling demand for cars and electronics has caused Japan's exports to drop by almost half, prompting companies to slash business travel.

All Nippon Airways Co. and Japan Airlines Corp., the airport's biggest users, have cut flights there this year, reducing revenue.