Suncor Energy is a Canadian integrated energy company based in Calgary, Alberta. It specializes in production of synthetic crude from oil sands. Suncor ranks number 134 in the Forbes Global 2000 list.
Until 2010, Suncor marketed products and services to retail customers in Ontario through a downstream network of 280 company-owned, and 200 customer-operated retail and Diesel fuel sites, primarily in Ontario under the Sunoco brand.
In 2009, Suncor acquired the former Crown corporation Petro-Canada, which replaced the Sunoco brand across its existing outlets. Suncor also markets through a retail network of Shell and ExxonMobil branded outlets in Colorado.
Suncor is the world's largest producer of bitumen, and owns and operates an oil sands upgrading plant near Fort McMurray, Alberta, Canada. Originally developed by Great Canadian Oil Sands, a majority-owned subsidiary of Sun Oil, it is now wholly owned by the independent Suncor.
According to en.wikipedia