De Beers continued with its policy of offering flexibility to its diamond buyers in view of the current weak demand for rough, according to Bloomberg.
Unnamed people who attended the September sightholders sales last week in Gaborone, Botswana said the firm allowed buyers to reject half the stones in each parcel offered.
They were also given room to sell back some diamonds to De Beers on favorable terms.
“This year, buyers have grown increasingly frustrated with the cost of rough diamonds sold by De Beers as the prices of polished gems slumped,” said Bloomberg.
“That’s led to wafer thin margins for their buyers and in some cases losses from the stones bought from De Beers and Russian rival Alrosa PJSC.
“The industry’s problems are centred around an oversupply of polished diamonds that have led to much steeper price drops than for rough stones.”
De Beers chief executive Bruce Cleaver said last July that there are no structural problems in the industry, although he accepts it’s not an easy time for clients.
The group sold $280 million of diamonds at its August sale, 44% less than a year earlier.
Its sales so far this year are about $1billion lower than the previous year.