Why are some foreign companies planned on NYSE and others on their own national exchanges?
Answers: Those that are listed on the NYSE as the 1st responder mentioned agree to follow SEC rules and want access to U S investors to possibly improve their marketability. There are not profusely. Only a small portion of the total number of companies that are traded world wide. Those that are traded on the NYSE in reality trade what are know as ADRs--American Depository Receipts. They are not exactly the same as the stocks they trade on their home market. The main difference human being that ADRs are traded in dollars and the dividends are remunerated in dollars but nearby is a conversion one into the other. It may not be on a one for one basis however. It can be 1 for 5 or some other ratio. Some are even 1000 for 1. Some foreign companies trade on the U S OTC flea market and even as native shares, not ADRs. They do however trade surrounded by dollars, not the local currency.
Any qualifying company can be nominated on the NYSE without good opinion to nationality if it pays the list fee and agrees to comply next to NYSE and SEC financial reporting rules.
Some large US companies are tabled outside the US as a convenience to their non-US investors.
http://www.investopedia.com/terms/a/adr.