�Diamond production for the third quarter at Zvishavane-based Murowa Mine increased to 92 000 carats, up from 72 000 carats produced in the corresponding period last year, parent company Rio Tinto has reported. In an update, the mining conglomerate said output at Murowa - the smallest of its three diamond mines - had increased by 28 percent.

"Murowa's diamond production for the first nine months of the year also grew to 215 000 carats, up from 198 000 carats mined in the same period last year," it said.

Rio Tinto plc owns 78 percent of Murowa Diamonds while RioZim Limited, an independent Zimbabwean-owned and listed company, holds the balance.

Three kimberlite pipes were discovered on the mine site in 1997, leading to feasibility studies and mine planning from 1998 to 2000, culminating in the commissioning of a small-scale operation in 2004.

The resource has the potential to be expanded to six or seven times its current production level, with a review of the feasibility study for this expansion currently underway. Murowa Diamonds employs around 180 people directly and 150 full-time contractors.

Meanwhile, Rio Tinto also reported that its other mines in Australia and Canada produced 2,4 million carats and 1,1 million carats respectively in the period under review.

The group's overall diamond output increased to 3,7 million carats during the period under review. Rio Tinto said its overall diamond production also increased 13 percent to 9,8 million carats during the first nine months of the year.

Diamond output continues to increase in Zimbabwe with the KP recently reporting that the country was now the world's fifth largest diamond producer after it exported 7,15 million carats of diamonds last year.

Other diamond mining firms operating in Zimbabwe include Marange Resources, Mbada Diamonds, Anjin and Diamond Mining Corporation which are all operating in Marange at the Chiadzwa fields.

Western countries led by the United States have been trying to block Zimbabwe from selling its diamonds as they fear the proceeds would enable it to overcome the effects of the sanctions imposed on the country as punishment for implementing agrarian reforms.