Imperial Oil Limited (French: L'Impériale) is a Canadian petroleum company. It is Canada's second-biggest integrated oil company. Exxon Mobil Corp. had a 69.6 percent ownership stake in the company as of December 31, 2012. It is a significant producer of crude oil, diluted bitumen and natural gas, Canada’s major petroleum refiner, a key petrochemical producer and a national marketer with coast-to-coast supply and retail networks. Its retail operations include Esso-brand service stations and On the Run/Marché Express and Tiger Express-brand convenience stores. It is also known for its holdings in the Alberta Oil Sands. Imperial owns 25 percent of Syncrude, which is one of the world’s largest oil sands operations. Imperial is also in a joint venture oil sands mining operation with ExxonMobil