Air China is engaged in the provision of air passenger and air cargo services; aircraft maintenance, repair and overhaul services; airport ground handling services; air catering services and other airline-related services. Through its subsidiaries and associated companies, Co. is also engaged in investment holding; import and export trading; manufacturing and retailing of aircraft supplies; and provision of travel agency, freight forwarding services, shuttle bus services, engineering consultancy services, aviation data communication services, airline-related information system services and financial services. As of Dec 31 2005, Co. operated a fleet of 176 aircraft.