Some 58 leaders from Europe, Latin America, and the Caribbean had gathered in the Austrian capital to discuss new trade and investment deals; but talks were dominated by concern over the two South American nations’ nationalist outlook.

Hugo Chavez, the Venezualan president, and Evo Morales, his Bolivian counterpart, run countries with strategically important energy supplies, and EU leaders have warned them that their policies can hinder economic growth and urged them to open up their markets.

Wolfgang Schuessel, the Austrian chancellor, said it was the two countries' choice to restrict investment;  "but the reality is ... open market societies are better in their performance than closed, restricted structures."

The summit was also overshadowed by a potential diplomatic rift between Bolivia and Brazil over Morales’ decision on May 1 that his country would nationalise its gas sector, giving foreign oil firms six months to negotiate new contracts or leave.

Brazil talks

"Neo-liberalism has begun its decline and has come to an end"

Hugo Chavez

On Thursday, Morales accused Petrobras, Brazil's state-owned oil firm and the largest foreign investor in Bolivia, of operating illegally in the country under "unconstitutional" contracts.

Morales, speaking at a news conference before the start of the summit, also warned that some companies might not be compensated for their investments in Bolivia.

On Friday,Celso Amorim, Brazil's foreign minister, said in response that his government had not ruled out pulling its ambassador to Bolivia in protest.

He urged Morales to ensure Petrobras would be compensated if Bolivia seizes company assets there.

"We will act firmly, but not hastily. Don't wait for Brazil to do it precipitously, but this does not exclude a strong reaction," Amorim told reporters.

At the close of the summit, Morales said he would meet with Luiz Inacio Lula da Silva, the Brazilian president, on Saturday morning, before EU talks with regional groupings such as Mercosur.

He also said that he wanted Petrobras to stay in Bolivia, and to keep Brazil as a key ally.

Pro-market condemnation

Chavez and his policies have
dominated talks in Vienna

However, Bolivia may not be participating in the proposed talks between the EU and the Andean community after the government expressed doubts.

But Alejandro Toledo, the outgoing Peruvian president, said the talks might proceed with just his country, Ecuador and Colombia taking part.

Elsewhere at the summit ,Chavez condemned the pro-market policies many Latin American countries have adopted in the last 20 years; but which have now fallen out of favour with many voters as they have had little effect in eradicating poverty.

"Neoliberalism has begun its decline and has come to an end," he told reporters.

"Now a new era has begun in Latin America. Some call it populism, trying to disfigure our beauty. But it is the ... voice of the people that is being heard."

European Commission President Jose Manuel Barroso declined to comment on specific states but said populism was a threat.

"We are a Europe against populist tendencies," he said.