Alaska Airlines agreed to buy Hawaiian Airlines in a $1.9 billion deal announced Sunday. The combined company would maintain both airlines’ brands, an unusual move in an industry where waves of acquisitions have led to four big brands dominating the U.S. market. On Sunday, the companies said Alaska will pay $18 in cash for each share of Hawaiian, whose stock closed Friday at $4.86 after losing just over half its value in the year so far.
