This paper suggests two major factors which affect the discontinuities in industry evolution. The first factor refers to the technological discontinuities related to diffusion of emerging technologies. The second refers to the regulatory discontinuities related to the dynamics over time of structural variables: entry, exit, competitive structure, and concentration, as well as technological change. The leased line industry is sort of public utilities. It means that this industry is characterized by technological and regulatory discontinuities. In this paper, it has been conducted comparative case studies among the four countries: Korea, United States, United Kingdom and Japan. Through the multinational case studies, three findings are suggested. The first is that late mover in public utilities may accelerate technological innovation in the industry evolution. The second is that deregulation in public utilities can promote the emergence of a significant competitor that is equal conditioned with the dominant player. The last is that the appearance of a significant competitor may get more fierce competitions in the public utilities.