TOKYO (AP) - Japan Airlines, wooed for months by Delta Air Lines with promises of cash and a broad global network, is spurning the world's biggest carrier and opting to keep its alliance with American Airlines.

Japan's flagship carrier says it will strengthen its partnership with American and apply to the U.S. government for antitrust immunity on trans-Pacific flights.

Antitrust immunity, the key to a closer revenue-sharing relationship between U.S. and Asian carriers, would likely have been difficult for JAL to achieve with Delta, a member of the SkyTeam alliance, because of competition concerns.

There is no guarantee American and Japan Airlines will be able to get antitrust immunity, either. But JAL, which is restructuring in bankruptcy, in the end wasn't willing to take the risk of moving to Delta.