"Matt Barrow" wrote in message
...

They used to say that the phone company or the utility companies needed to
be monopolies.


That's not quite the same situation. True competition between phone and
utility companies would require each company to create their own
distribution networks in the same area. Separate phone, gas, and electrical
lines for each company. It could be done but at greater cost to the
consumer and less profit for the company.

You could have separate ATC providers, each providing their own
infrastructure in the form of radar sites, radio transceivers, etc., but
their clients would all be operating in the same airspace. Customers of
Acme ATC would be separated from other Acme ATC customers, and Consolidated
ATC clients would be separated from each other, but Acme ATC customers could
not be separated from Consolidated ATC clients.