The two continents are expected to commit to a series of measures to boost trade, and exchange technologies that will add value to their raw materials. They hope to set up an Africa-South America bank to finance infrastructure projects.
A draft declaration from the summit talks of "establishing inter-regional partnerships" with respect to energy and calls for a swift conclusion to the Doha Round of World Trade talks..
Obasanjo said the development of economic ties would put Africa and South America in a good position in the context of global opportunities.
"The need for us, as developing countries, to rally to our own assistance remains important"
Olusegun Obasanjo, the Nigerian president
"Our objective here, therefore, should be to give further impetus and practical expression to the ideals of South-South cooperation which has for long engaged the attention of our two regions in various fora," he said.
The summit also seeks to address reform of the United Nations, whereby "equitable participation of developing countries" is promoted.
But the two continents still have diverging views on who exactly should get a permanent Security Council seat.
Trade and energy talks
Four Opec countries are represented at the summit and the subject of oil is more likely to arise during bilateral talks, particularly given that Nigeria is hosting its first Opec summit in Abuja on December 14.
In his opening address, Obasanjo said the two continents should take their destinies in their own hands rather than rely on external assistance.
"The need for us, as developing countries, to rally to our own assistance remains important, given the increasing economic and financial gap between the rich and poor nations of the world," he said.
The leaders from South America included Luiz Inacio Lula da Silva, the Brazilian president; Alfredo Palacio, the Ecuador president; Ronald Venetiaan of Surinam and Bharrat Jagdeo of Guyana.
Those from Africa included Muammar Gaddafi, the Libyan president, Abdelaziz Bouteflika, the Algerian president, Armando Guebuza, Mozambique's leader and Faure Gnassingbe, the president of Togo.
Other leaders were yet to arrive at the summit, organisers said.