Japan Airlines and China Eastern Airlines said Thursday they have agreed to introduce comprehensive code-sharing beginning Sept. 1 to cope with an expected increase in demand for passenger and cargo flights.

"The code-share agreement will provide both carriers with greatly enhanced schedule variation that will be of substantial benefit to their customers," JAL and China Eastern said in a joint statement.

JAL's first code-sharing agreement with a Chinese carrier covers 13 flights on four air routes.

Under the agreement, travelers to Shanghai from New Tokyo International Airport, in Narita, Chiba Prefecture, will have a choice of three departures a day: a morning flight with JAL, a lunchtime flight with China Eastern and an evening flight with JAL.

The route linking Kansai International Airport on Osaka Bay and Qingdao will also be expanded via the agreement.

Since April, JAL and China Eastern have been operating four freighter flights per week.

China Eastern is one of China's six airlines.

Competition among airlines for footholds in the Chinese market is increasing due to an expected sharp increase there for flight services.

Among other Japanese carriers, All Nippon Airways, which was in a partnership with China Eastern until May, concluded a comprehensive code-sharing agreement with Southwest China Airways in April. Japan Air System code shares with China Southern Airlines.

The opening of the second runway at Narita airport in April boosted demand on Japan-China routes by increasing carriers' seating capacity by 115 percent on a year-on-year basis, according to JTB Corp., Japan's biggest travel agency.