By Julie Johnsson | American Airlines postponed the launch of its Chicago-to-Beijing service hours before the first flight was due to depart Monday because of a dispute with the Chinese government over landing slots.

The Texas-based carrier, which operates a major international hub at O’Hare, said it had postponed the start of service until May 4, and would rebook or provide refunds to passengers who had purchased tickets for the Monday flight.

“Until American receives viable operating slots, we will not be able to fly between Chicago and Beijing and thus cannot deliver air transportation services to the American and Chinese people,” the carrier said in a statement.

The dispute centers over the times at which American is allowed to use the airport in China’s capital city, a route it was awarded by the U.S. government in September 2007. When a spike in oil prices sent airlines into a steep downturn in 2008, American received permission to defer the start of its new service until 2010.

But Chinese aviation authorities slated the American flight’s arrival for 2:20 a.m. and its departure for 4:20 a.m., highly undesirable for international travelers with connecting flights within China.

American has been negotiating for mid-afternoon slots since October. It didn’t decide to postpone the launch of its service earlier because talks were ongoing, and Chinese authorities had waited until the last minute to award better slots to other international carrier, said Mary Frances Fagan, an American spokeswoman.

Beijing restricts carriers to a maximum of 83 slots per hour, Fagan said. O’Hare, by contrast, allows 92 slots per hour during peak periods.