More than £1 billion was wiped from the value of Anglo American PLC after the De Beers owner finally agreed with its partners to cut diamond production.
It was the most newsy part of the mining giant's first quarter update from Anglo, which revealed a 23% year-on-year decline in rough diamond production to 6.9 million carats (Mct).
The plan is to cut output by 3Mct to 26-29Mct for 2024, thereby increasing unit costs from $80/ct to $90/ct.
"More supply needs to be taken out the market, from both the synthetics and more marginal natural rough, but we do expect the worse for diamonds to be over and a slow recovery to begin," said Liberum analyst Ben Davis.
In the update, Anglo maintained its other production goals.
Shares in the international mining giant were off 81.5p at 2,078.5p.