The Alto Cuilo site, in Angola, has the potential to contain "substantial" deposits of economic diamond-bearing material, while the Luangue work programme would focus on proving up the potential of enriched near surface resedimented volcaniclastic kimberlite deposits.

In May, Petra Diamonds assumed full control of these two project, after BHP Billiton transferred its rights in the joint venture to the junior miner.

Petra Diamonds also announced the discovery of a new kimberlite in the Orapa/Letlhakane area, close to Debswana's producing Damtshaa mine.

The discovery extends northwards into the Debswana mining licence, and the portion in Petra's licence areas could represent 20% to 30% of the total kimberlite.

The company has been in contact with Debswana in relation to this discovery, Petra said in a statement.

"These promising results from our programmes in Angola and Botswana, where we have some of the world's most prospective diamond exploration ground, are highly encouraging and firmly underpin Petra's growth prospects.

Our exploration projects, combined with our rapidly growing production in South Africa, support Petra's fast growing status as a leading diamond company," commented Petra CEO Johan Dippenaar.

In South Africa, Petra has five producing mines and recently reached an agreement to buy Kimberley Underground mines from De Beers. The group plans to lift its yearly output from 180 000 ct/y to around one-million carats a year in June 2009.

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