What does a company need to have in order to be considered a monopoly? Is there a legal definition of monopoly in the U.S.A.? For the E.U. I quote Wikipedia:

What does a company need to have in order to be considered a monopoly? Is there a legal definition of monopoly in the U.S.A.? For the E.U. I quote Wikipedia: "By European Union law, very large market shares raise a presumption that a company is dominant, which may be rebuttable. If a company has a dominant position, then there is "a special responsibility not to allow its conduct to impair competition on the common market". The lowest yet market share of a company considered "dominant" in the EU was 39.7%." http://en.wikipedia.org/wiki/Monopoly#Law http://en.wikipedia.org/wiki/Monopoly#Law