The European Commission, calling De Beers "dominant" in the rough diamond sector, has barred the diamond industry giant from buying existing mines, South Africa's Business Day reports.

While De Beers does not agree, says acting joint CEO Stuart Brown, it does not want to put the EC's decision to a test by making another acquisition at this point.

According to De Beers, it accounts for 33%-36% of global rough diamond production. Last year, De Beers produced some 33 million carats, and 2011 production is expected to reach 38 million carats and rise again to 40 million carats in 2012.

De Beers is also working on a major expansion of the Jwaneng mine in Botswana, the world's most profitable diamond mine, and is a joint partner in the Gahcho Kue diamond project in Canada. If the Gahcho Kue project receives a green light for development, it is at least six years away from being a viable diamond producer, Brown noted.

This year, De Beers is also expected to decide whether to approve plans to build an underground mine at its Venetia project in South Africa.