The presidents of Bolivia, Venezuela and Argentina have signed joint energy deals worth more than $1bn in Bolivia.
Mr Chavez and Mr Morales head energy-rich nations
The accords come at the end of a regional tour by Venezuelan leader Hugo Chavez. He signed bilateral energy deals in the four countries he visited.
During his trip, Mr Chavez has repeatedly attacked the US for trying to dominate world energy supplies.
He has pledged to use Venezuela's oil wealth to help guarantee the energy needs of his allies in Latin America.
Mr Chavez, his Bolivian counterpart Evo Morales and Argentina's leader Nestor Kirchner met in the southern Bolivian city of Tarija.
Mr Morales and Mr Kirchner finalised a $450m agreement to build a gas processing plant in the border region of Chaco and in the Amazon region north of La Paz.
This deal came after Mr Chavez signed an accord with Mr Morales on Thursday to create a $600m joint venture, Petroandina, formed by Venezuela's state-run oil company PDVSA and Bolivia's state energy company YPFB.
Mr Chavez has pushed energy integration through public investment throughout the tour.
"The story of neoliberal globalisation was that privatisation was going to bring us big investment. That was a lie," he said.
"The delivery of our natural resources to transnational companies... left us only underdevelopment, technological backwardness, poverty, misery and dependence."
Mr Chavez's tour has also taken him to Argentina, where he announced plans to buy up some $1bn (£500m) in Argentine government bonds.
In Uruguay, he discussed ways of expanding the country's oil refining capacity and promised Uruguayans that they would be provided with oil and gas for a century.
Mr Chavez then travelled on to Ecuador, where he signed an agreement with President Rafael Correa to build a giant oil refinery costing some $5bn.
During his visits, the Venezuelan leader has again spoken out against the US and capitalism, telling his allies that they needed to work together to make South America strong.
Mr Chavez's domestic opponents have criticised what they see as hand-outs of Venezuelan wealth for political gain.
But Mr Chavez says that the deals signed during his trip will bring mutual benefit to the countries involved.