Alaska Airlines said on Wednesday it had completed its $1.9 billion acquisition of Hawaiian Airlines after reaching an agreement with the U.S. Department of Transportation.

The airline’s chief executive, Ben Minicucci, said in an interview that closing its acquisition of Hawaiian Airlines would allow it to expand, including on international routes.

The vast majority of non-union jobs – plus all of Hawaiian’s 6,000 union workers — will remain untouched by Alaska’s acquisition of Hawaiian, said Joe Sprague, a former longtime Alaska executive who succeeds Peter Ingram as Hawaiian’s interim chief executive.