In the USA there is The Genetic Information Nondiscrimination Act from 2008 that bars insurance discrimination based on your genes. I assume this will become a landmark law in the next 50 years as society becomes familiarized with routine blood (I mean gene) tests to drive preventive care to the next level
This is also an issue with subways. NYC subway, for example, originally had two different owners and they build their separate networks with different width so that one rail would not use the other. Today, they call it Division A and B trains.
Public-traded companies are independent, so no merger or consolidation applies. Here is what the U.K. regulatory body defines a 'relevant merger' (regardless if U.K. or internationally-based):
the creation of a relevant merger situation as defined in section 23 of the Enterprise Act 2002 (“the Act”), in that:
(a) two or more enterprises will cease to be distinct;
(b) in the course of the enterprises ceasing to be distinct, a person or group of persons will bring a relevant enterprise (as defined in section 23A of the Act) under their ownership or control; and
(c) the value of the turnover in the United Kingdom of the enterprise being taken over exceeds £1 million.
“Be curious, not judgmental” – Walt Whitman