What about an Indonesian company holds 40% of a company, and a Malaysian company hold another 40% of a company. And the rest 20% of shares is hold by a Singapore airline. Assume both 40% contains same mount of shares. Now you have two majorities. How the system determine the country of the airline?
Random between the Indonesian and Malaysian companies. See Martins post above...
Consider shares of a US company - if a China company owned 40%, and two USA companies owned 30% each - USA is the legal country but is fully controlled by a Chinese company?
That brings a whole range of possibilities.
Yes, buy the two USA companies must be active fully operating airlines, not just financial companies set up for purpose of giving a third company (manager) the traffic rights.
BTW, a little of topic, but are there other requirements than the 20 mil equity for a company to try to IPO ? Ie can i setup a company with20 mil and IPO it immediately ?