The links among securities trading processes in different countries may take various forms. The most common version, applied also in such examples as trading between Argentina and Brazil and within CARICOM, is a correspondent relationship between the brokers in each country involved in the transaction.
An other important step towards the linking of domestic exchanges within the same region involves the listing of one country's enterprises on the stock exchanges of other countries and/or in the intra-regional electronic trading system. Such an arrangement may lead also to parallel listings, a phenomenon quite common in Europe. It means that, on condition that the necessary regulation is harmonized, the same company (with preferably regional business activities) is authorized to list its shares on more than one country's stock exchange at the same time. If countries mutually agree to introduce bilaterally balanced cross-border listings they can form a scheme of cross-listings.
The linking of trading processes implies the establishment of a communications network and eventual cooperation schemes among all the interested domestic actors. The custody, settlement and clearing institutions should establish, among themselves, all the necessary channels for settling the balances and transferring the ownership certificates. The settlement mechanism naturally entails the participation of central banks. The listed companies and the interested potential investors may communicate, respectively, via their chambers of commerce and their associations. Finally, telecommunications companies should reach an agreement on the future compatibility of their systems.