Northwest Airlines and Hawaiian Airlines have  teamed up to offer a code share agreement. With Northwest’s strength in the Hawaiian market it  will soldify Hawaiian Airlines position with the competition from Mesa’s Go! Airlines entry this past week.

That means Northwest customers who fly to Honolulu and connect to Kauai, Maui or Hawaii’s Big Island will transfer to a Hawaiian Airlines interisland flight (although they also can book other airlines if wished). The code-share agreement also allows passengers enrolled in one airline’s frequent-flyer programs to earn frequent-flyer miles by flying the other airline.
Northwest flies more than 50,000 passengers to and from Hawaii per week, including from Seattle. Honolulu-based Hawaiian provides 100 interisland flights each day. via The Seattle Times