The changes in Venezuela are being reflected elsewhere in Latin America.

Mr Chavez's allies in Bolivia and Ecuador are making similar moves.

"The neo-liberal governments gave away hills, rivers and mining concessions. We have to start recovering those concessions," Bolivia's President Evo Morales said before starting the process of nationalising the gas industry.

But critics question whether Mr Chavez's "21st-Century socialism" can be exported to countries that do not have the oil wealth of Venezuela.

It's a nervous time for investors and private companies.