De Beers will soon announce new set of strict rules for companies wanting to join its coveted group of customers known as “sightholders”, says a report.

The report further adds that, under the new rules, sightholders will have to present their accounts according to international standards. De Beers will also insist customers hold a specified proportion of equity in their businesses, making them less reliant on bank borrowing.

As per the reports, only about 80 companies — most from traditional diamond trading and polishing centres such as Antwerp, Israel or India — are approved by De Beers to become sightholders and take part in regular sales, or “sights”, each year where they buy rough stones.

De Beers had last reviewed its sightholder contracts in 2011. About a quarter of sightholders are compliant with international accounting rules. The report adds that some of the companies will be given time to make changes to their accounting practices. Any sightholders that are unwilling or unable to do so will lose the status of being a De Beers ‘Sightholder’.