JOHANNESBURG - South African President Jacob Zuma on Sunday launched Africa's biggest free trade bloc aimed at enhancing cooperation between 26 nations to boost economies in the world's poorest and underdeveloped continent.

"There is no single country that can prosper on its own," Zuma said at the launch of the initiative that will see three sometimes overlapping trade blocs join to create a $875 billion market.

"The Free Trade Area will certainly help us accelerate regional integration efforts aimed at ensuring that African countries trade with each other on better terms," he told African leaders attending the launch.

The Southern African Development Community (SADC), East African Community (EAC) and the Common Market for Eastern and Southern Africa (COMESA) will now work as a joint bloc.

The agreement will include about half the continent's nations but economic disparities and political instability in countries like Zimbabwe, Madagascar, Libya and Sudan are possible hurdles towards improved trade.

Inefficient bureaucracies, poor infrastructure, tariff barriers and weak supply chains are further challenges.