Rolls-Royce Holdings plc is a United Kingdom-based engineering company. The Company is focused on power and propulsion systems. Its segments include Civil Aerospace, which is engaged in the development, manufacture, marketing and sales of commercial aero engines and aftermarket services; Defence Aerospace, which is engaged in the development, manufacture, marketing and sales of military aero engines and aftermarket services, and caters to sectors, including combat aircraft, trainer aircraft and helicopters; Power Systems, which is engaged in the development, manufacture, marketing and sales of reciprocating engines and power systems; Marine, which is engaged in the development, manufacture, marketing and sales of marine-power propulsion systems and aftermarket services, operating in offshore, merchant and naval markets, and Nuclear, which is engaged in the development, manufacture, marketing and sales of nuclear systems for civil power generation and naval propulsion systems.