Alaska Air Group has promoted Brad Tilden to chief executive, replacing Bill Ayer, who is retiring after leading the company since 2002.
Tilden, who is president of Alaska Airlines, will oversee Alaska Airlines and regional carrier Horizon Air.
The change, announced in February, became effective at the Alaska Air Group's annual shareholder meeting.
Tilden, 51, retains his role as president of Alaska Airlines while Ayer remains chairman of Alaska Air Group's board.
Tilden joined the airline from Price Waterhouse in 1991 and has served as the company's chief financial officer and executive vice president of planning and finance.