Alaska Air (AL) and Hawaiian Holdings (HA) disclosed earlier that they agreed with the Department of Justice to further extend the merger review period until 12:01 a. m. Eastern Time on August 20. “Alaska and Hawaiian continue to cooperate with the DOJ in this review process,” the companies said in a regulatory filing. Shares of Alaska Air closed Thursday up 2% to $35.30 while Hawaiian closed up 10% to $16.46.