Hawaiian Airlines has seen its shares tumble 9% amid a report that the US Department of Justice may unlikely approve its intended $1.8 billion sale to Alaska Air Group. The merger would see the two carriers serve more than 54.7 million passengers annually to 138 destinations across the Americas, Asia, Australia, and the South Pacific, including nonstop destinations to 29 top international ports. Furthermore, the combined carrier will offer more choices for passengers than either carrier could do before.