MTU Aero Engines is a company that manufactures engines. It operates through two segments: OEM (commercial and military engine business) and MRO (commercial maintenance business). The OEM segment develops, manufactures, assembles, and delivers commercial and military engines and components. The segment also offers maintenance, repair, and overhaul services for military engines. The MRO segment maintains, repairs, and overhauls aircraft engines and industrial gas turbines. In addition, this segment provides engine module and parts repairs as well as related services, such as engine leasing.