Diamond miner De Beers expects to produce about 32-million carats for the full-year, which is at the lower end of its initial guidance of 32-million to 33-million carats.
Reporting on its production performance in the third quarter ended September 30, the Anglo American subsidiary said demand for rough diamonds remained robust.
Positive midstream sentiment also reflected strong demand for polished diamond jewellery, particularly in the key markets of the US and China.
De Beers sold 7.8-million carats of rough diamonds in the third quarter, which included two sight sales.
That compares with the 6.6-million carats sold in three sight sales in the third quarter of 2020 and the 7.3-million carats sold in two sight sales in the second quarter of this year.
De Beers' rough diamond output increased by 28% year-on-year to 9.2-million tonnes in the third quarter.
The miner noted that this reflected the planned higher production to meet stronger demand for rough diamonds.
In Botswana, production increased by 33% to 6.4-million carats, primarily as a result of the planned treatment of higher-grade ore at Jwaneng, but partly offset by lower production at Orapa owing to the planned closure of Plant 1.
Production in Namibia increased by 65% to 400 000 ct reflecting the suspension of the marine fleet during the third quarter of 2020, as part of the response to lower demand at that time.
De Beers' South African production increased by 34% to 1.6-million carats as a result of the planned treatment of higher-grade ore from the final cut of the Venetia openpit and an improvement in plant performance.
Production in Canada decreased by 13% to 800 000 ct owing to lower-grade ore being processed.