Mitie has won a five-year extension to its existing contract worth £17 million, which includes a new agreement to maintain electrical services.
The facilities management and professional services company has been working with Gatwick for the past seven years and will now maintain the relationship until at least late 2023.
Gatwick, which is the UK's second largest airport, will benefit from Mitie's expertise in large-scale FM services including building and plumbing services, cleaning and looking after flooring, fire doors and drainage.
The contract, to provide critical support services including electrical engineering, will cover the North and South terminals and property buildings.
Carlo Alloni, managing director of engineering and IFM at Mitie, said: "We have spent the past seven years supporting Gatwick Airport and the many passengers who pass through its terminals We know airports are challenging environments in which to deliver facilities management and over the years, Mitie has proved to Gatwick that we can deliver service excellence, which is both resilient and cost-effective. It is also paramount that this is all done with minimal disruption to its passengers."