DIAMOND company De Beers said it sold $520m worth of diamonds in the sixth out of 10 annual sales during August, a reduction of $44m compared with the previous event.

De Beers, which is 85% owned by Anglo American and 15% by the Botswana government, was expected to report a slowing of rough diamond sales in the second half of the year due to seasonal issues.

“This is an encouraging sales performance for this point in the year, supported by positive sentiment from our customers. We maintain a cautious outlook for the remainder of 2016,” said new CEO Bruce Cleaver.

De Beers has so far this year reported sales of $3.548bn with four sales left to go ahead of the build-up to the year-end and Christmas sales in the US, which is the largest diamond jewellery market in the world and in which most diamond jewellery buying happens in the run up to the year-end.

The August sales of $520m were the lowest so far this year and well off the peak of $666m recorded for the third sale in April.

De Beers is by far the biggest source of earnings within Anglo and will remain one of three core divisions as the diversified miner sells tens of bulk commodity mines, reducing its portfolio of more than 40 assets to just 16 in diamonds, platinum and copper.