The present article analyses the origins of Brazilian electric utility considering the possible existence of conflicting evidence that gives support both to The Theory of Regulatory Capture and Interest Groups and the Theory of Regulation Transaction Costs. American regulatory debate is frequently characterized by these sharply distinct theories. Such theories arrogate the explanation of US energy regulation origin. Otherwise, analyzing the evidence on the origin of electricity utility in Brazil, at first sight they are conflicting, setting ground both to The Theory of Regulatory Capture and Interest Groups and also the Theory of Regulation Transaction Costs. The present article proposes an integrative theory that weights the pieces of evidence to better explain the origins of Brazilian electric utility.