Montevideo is the seat of the administrative headquarters of Mercosur and ALADI, Latin America’s leading trade blocs, position that entailed comparisons to the role of Brussels in Europe.

Mercosur or Mercosul (Spanish: Mercado Común del Sur) is a sub-regional bloc. Its full members are Argentina, Brazil, Paraguay, Uruguay and Venezuela.

Its associate countries are Bolivia, Chile, Peru, Colombia, Ecuador and Suriname.
Observer countries are New Zealand and Mexico.^]

Its purpose is to promote free trade and the fluid movement of goods, people, and currency. The official languages are Spanish, Portuguese and Guarani. It has been updated, amended, and changed many times since. It is now a full customs union and a trading bloc. Mercosur and the Andean Community of Nations are customs unions that are components of a continuing process of South American integration connected to the Union of South American Nations.

The port on Montevideo Bay is one of the reasons the city was founded. It gives natural protection to ships, although two jetties now further protect the harbour entrance from waves. This natural port is competitive with the other great port of Río de la Plata, Buenos Aires.