(ShareCast News) - Construction and maintenance company Carillion extended its partnership with utility firm Centrica for a further five years to deliver facilities management and project services, in a deal worth £90m.The service is to start in December and builds on the company's existing decade-long management service for Centrica's British Gas business and will now include total facilities management.The deal, which can be extended to seven years, will see Carillion provide asset surveys and planning, planned and reactive maintenance, cleaning, security and catering for Centrica's 115 sites across the UK.Carillion's chief executive, Richard Howson, said: "We have worked closely with Centrica since 2005 and built a strong partnership."We are delighted to be extending this relationship, which is based on a one-team approach in which Carillion and Centrica work together to deliver award-winning standards of facilities management and customer service across all Centrica and British Gas sites."