Workers affiliated with three American Airlines unions have agreed to support a potential merger with U.S. Airways Group, CNNMoney reported, citing a U.S. Air document filed with the Securities and Exchange Commission today.

The unions represent 55,000 pilots, flight attendants and transport workers. The airline pointed out that a deal has not gone through yet.

“It only means we have reached agreements with these three unions on what their collective bargaining agreements would look like after a merger, and that they would like to work with us to make a merger a reality,” U.S. Airways CEO Douglas Parker said in a letter to his employees.