The owner of Alaska Airlines and Horizon Air said the additional shares will be distributed on July 9 to shareholders of record as of June 23.
The stock split will double the company’s outstanding shares to about 136 million shares.
This is the Seattle company’s second stock split since going public. Alaska Air said the last one was in March 2012.
Its shares fell $3.51, or 3.6 percent, to $93.33 in afternoon trading Thursday. They had been up 32 percent so far this year through Wednesday’s close.