Rolls-Royce Aerospace Engines

Rolls-Royce Aerospace Engines is the leading producer of both aerospace engines and power generators for the UNSCDF and civillian market. RRAE is almost 700 years old, having been formed as 'Rolls-Royce plc.' in 1906. For most of that time it has been one of the highest competitors for producing engines for maritime and aerospace use and power generators. With the consolidation of north American companies into the United North American Defence Systems, came a weakness to their main competitor, General Electric, through internal manouvres and miss appropriation of internal resources and managment. With the Human-Covenant war they became the producer of the jet engines in the Longsword fighter and producer of the mammoth rocket engines that proppelled the UNSC Frigate vessels, along with working in tandem with Dr. Halsey and ONI to design the new power plant for the UNSC Pillar of Autumn, provide more of these powerplants for newer vessel classes and create power plants for the Marathon-class Cruiser and the Destroyer class in service. 
In the afterwar period they bought the production rights to the new Plasma-Fusion Core, which were consequently used on nearly every Human vessel, along with many vehicles, infantry and other uses, becoming its highest selling product. They also provided the engine systems for the Knife and Katana Fighter, the Broadsword and provided Rocket engines for half of the in service UNSC vessels.