Phoenix-based Mesa Air Group placed a firm purchase order for seven Bombardier CRJ900s worth $326 million at list prices after securing a new 10-year contract with American Airlines to fly the 76-seat jets under the American Eagle brand. Bombardier and Mesa inked the contract during the March 8 to 11 International Society of Transport Aircraft Trading (ISTAT) Americas 2015 conference held in Mesa’s hometown.

Once filled, the order will take Mesa’s CRJ900 fleet to 64 airplanes. The contract calls for the airline to receive the first of the jets in July and the last in September.

Since March 2013 Mesa has doubled in size, adding 19 CRJ900s to the fleet it operates for American and 19 new Embraer E175s for United Airlines. The addition of the latest tranche of CRJ900s along with 11 new E175s scheduled for delivery promises to raise Mesa’s fleet total to 115 aircraft by year-end.