Term from economics that describes an oligopoly in the context of investment intensive infrastructure

Question

I know that this word exists as I was on a Wikipedia page describing this phenomenon. The problem is that I forgot the word.

The word describes the situation that there is no real competition in markets where the initial investment costs are huge. For example, in the energy industry, there are often oligopolies and new contenders do not emerge due to the huge initial investments they had to shoulder in order to run a business that even has a chance to become profitable.

Answer 1

A situation like you describe is sometimes denoted as "Natürliches Monopol"

http://de.wikipedia.org/wiki/Natürliches_Monopol