Meeting in the Angolan capital of Luanda on Saturday, 12 diamond producing African countries formed the African Diamond Producing Countries' Association.
Seven other nations from the continent participated as observers.
Africa accounts for more than 60 per cent of the world's diamond production and the association is aimed at protecting African diamond prices and production and at helping to stem the illegal trade in conflict diamonds.
Manuel Africano, Angola's mining minister, said that despite the large amount of diamonds produced in Africa, the continent "had no say in world diamond commerce strategies".
Africano said Africa, which includes the world's largest diamond producer Botswana, generated about $158 billion a year from the trade of 1.9 billion karats.
The diamond industry represents 33 per cent of Botswana's gross domestic product, while Angola produces almost $1 billion worth of diamonds annually and aims to double its production in the next year.
Conflict diamonds have long fuelled African wars, with armed factions selling gems to raise funds for weapons.
In 2002, the United Nations backed the Kimberley Process Certification Scheme, a programme launched to certify the origins of rough gems. It allows the diamond industry to block stones mined in conflict zones from sale in overseas markets.
The Kimberley Process's 45 participants account for approximately 99.8 per cent of the global production of rough diamonds.
Sanctions on Liberia
Africano said that the Kimberley Process had helped to almost fully eradicate the commerce of so-called blood diamonds.
"We wish that sanctions be lifted as soon as possible and we are willing to help Liberia fulfill the international requirements needed to see this through"
A statement by the ministers forming the association
Ministers from the newly formed association also appealed for the UN to lift sanctions on Liberian gems.
The Security Council imposed arms and diamond embargoes on Liberia in May 2001 during a 14-year civil war, which ended in 2003 with a peace deal and a national-unity government. Last month the UN decided that the ban should remain in place.
"We wish that sanctions be lifted as soon as possible and we are willing to help Liberia fulfill the international requirements needed to see this through," the ministers said in a statement.
The association's members include Angola, South Africa, Botswana, Ghana, Guinea, Congo, Sierra Leone, Tanzania, Togo, Zimbabwe, Namibia, and Central African Republic.