Utilize the input text as a context reference, choose the right relationship between CENTRICA and energy supply from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

* CENTRICA - Britain's largest utility will sell up to 1 billion pounds worth of upstream and wind assets by 2017 and reduce net headcount by around 4,000 staff in a strategy shift that will see it put more emphasis on energy supply and services.

Answer: industry