De Beers has cut diamond prices by more than 10% across the board as the world’s biggest producer abandons attempts to put a floor under the slumping market.

The diamond industry has been struck by one of its deepest and most prolonged slumps in decades. What started as a post-pandemic slowdown has spiraled as inflation hit customer purchases, before a collapse in China’s luxury market further eroded demand. Man-made diamonds have also continued to undermine prices.

As rough diamond prices in the secondary market — where traders and manufacturers buy from each other — have steadily dropped through most of the year, De Beers attempted to hold the line. The unit of Anglo American offered its customers more flexibility and the right to refuse goods rather than lowering prices.

Yet on Monday, the company capitulated on that position at its final sale of the year. De Beers cut prices by 10% to 15% for most of the goods it sells, according to people familiar with the situation. That’s the first major price cut since the start of the year and a historically large reduction.

A spokesman for De Beers declined to comment.

The slump in the diamond market comes at a difficult time for De Beers. Its owner, Anglo American, is looking to exit the business as part of a radical restructuring after fending off a $49-billion bid from BHP Group earlier this year.

De Beers wields considerable power in the rough-diamond market. It holds 10 sales each year in which the buyers — known as sightholders — generally have to accept the price and the quantities offered.

Still, even after the steep cut in prices today, the company’s stones are still more expensive than the going rate in the secondary market, the people said, asking not to be identified as the matter is private. The company also removed some of the flexibility it had offered at previous sales.

De Beers typically reserves aggressive price cuts as a last resort. While it keeps pricing secret, the across-the-board cut this month is hefty.