Japan Airlines Co. and British Airways signed an agreement Wednesday to form a comprehensive alliance to jointly launch frequent flier programs and code-sharing operations.

The two carriers plan to start joint frequent flier programs on April 1 and code-sharing on an Osaka-London route this summer. The code-sharing plan is subject to permission from the Japanese and British governments, according to the carriers.

Under the alliance, seven flights a week on the Osaka-London route operated by JAL will bear the flight numbers of both JAL and British Airways. British Airways will sell some of the seats on JAL routes.