Africa\'s largest trading bloc -- the Common Market for Eastern and Southern Africa (COMESA) -- has said non-tariff barriers were contributing to the high cost of business in the region, the Post of Zambia reported on Thursday. Francis Mangeni, who is director of trade at the COMESA secretariat situated in the Zambian capital Lusaka, said the barriers were reducing the gains from trade by restricting domestic market access to regional exporters. Non-tariff barriers were also denying consumers welfare enhancing opportunities which arise from access to reasonably priced regional imports, he added. \"The strong intra and inter-regional trade growth that is the target of the on-going negotiations for a tripartite trading arrangement from the current levels of less than 10 percent to.. over 25 percent should serve as a reminder of the prevailing potential for economic prosperity that we can all obtain thus alleviating poverty in our regions,\" he was quoted as saying by the paper at the start of a meeting on non-tariff barriers online reporting, monitoring and eliminating mechanism in Lusaka. The regional blocs, namely COMESA, the Eastern African Community (EAC) and the Southern African Development Community (SADC) have been holding discussions on the possibility of coming up with a tripartite free trading agreement. COMESA launched its free trading agreement in 2000. COMESA, with 19 member states, is the largest trading bloc in Africa with a combined population of 425 million people and a combined Gross Domestic Product (GDP) of 450 billion U.S. dollars.