Centrica plc is a British multinational energy and services company with its headquarters in Windsor, Berkshire. Its principal activity is the supply of electricity and gas to businesses and consumers in the United Kingdom, Ireland and North America. It also provides a range of services including energy trading, the installation and maintenance of heating and cooling systems and the provision of low-carbon and energy efficient products and services. Centrica is listed on the London Stock Exchange and is a constituent of the FTSE 250 Index.