The contract was put out to tender last year when the hospital laundry was forced to close after losing other hospital contracts.
The original laundry site has been earmarked for a new operating theatre as part of the hospital's expansion plans, so the laundry will move into a smaller building on the hospital site, as detailed in its proposal. The in-house team will run the linen service for three years.
Hospital chief executive, Gerry McSorley commented: "The in-house team is to be congratulated on its success. They faced tough competition from established companies and they put forward a very professional proposal which balanced price with quality of service."