The popular variant is a predecessor to the Boeing's 737 MAX, which awaits regulatory approval in China, the world's largest domestic aviation market. The 737-800 has a maximum seating capacity of 189 and is equipped with a CFM-56 engine, according to Boeing's website. It was not clear immediately if the aircraft involved in the accident had the same engine as airlines are free to choose engines from other suppliers. The CFM engines are made by a joint venture between General Electric Co and France's Safran SA. GE shares were down about 1%, while France-listed Safran fell 3%. The planemaker's shares fell 4.5% in early trading, while the Chinese airline's U.S. listed ADRs were down about 9%. Parts suppliers Spirit AeroSystems Holdings Inc, Hexcel Corp and Triumph Group Inc were down between 1% and 4%.