Jan 6 (Reuters) - Alaska Air Group Inc:

* ALASKA AIRLINES SAYS 18 OF ITS BOEING 737-9 AIRLINERS HAD IN-DEPTH PLUG DOOR INSPECTIONS PERFORMED RECENTLY, THOSE AIRCRAFT WERE RETURNED TO SERVICE SATURDAY

* ALASKA AIRLINES SAYS INSPECTION OF REMAINING 737-9 AIRCRAFT IS EXPECTED TO BE COMPLETED IN NEXT FEW DAYS - COMPANY STATEMENT Source text for Eikon: Further company coverage: (Reporting by David Ljunggren)