"Exxon" is a proper noun that refers to a large multinational oil and gas company. It is a well-known brand that operates globally, specializing in producing and selling petroleum and petrochemical products. Full definition
We still don't know the true impact of Exxon Valdez, and now it is clear we never will. (dotearth.blogs.nytimes.com)
For example, the Competitive Enterprise Institute, a think tank «advancing the principles of free enterprise and limited government», got, Greenpeace claims, about 2 million dollars from Exxon Mobil from 1998 to 2005. (climate-skeptic.com)
New estimates of the amount of oil spilled by Exxon Mobil in Mayflower, Arkansas have grown far beyond the initial figures. (treehugger.com)