Glencore has said it will reduce production targets at certain mining sites, particularly at its Cerrejon open-pit coal mine in Colombia, to address falling prices of some raw materials.

"Decades after decades, we have to take these tough decisions," said Glencore CEO Gary Nagle, adding that the company was hoping to reopen shut-down operations when prices improve.

"These are necessary actions we have to take to protect our business," he said.

Union representatives had bought shares to be able to intervene at the company's general assembly held in the Swiss city of Zug on Wednesday.

"Miners are going to lose their jobs," Glen Mpufane, the representative for the mining branch of the trade union organisation IndustriALL, told AFP.

Mpufane, who had travelled from South Africa to attend the assembly, blamed the company's lack of dialogue with trade unions.

Meanwhile, dozens of environmental activists had unfurled banners outside and laid out a world map on the floor covered with pieces of coal and red sand, symbolising river pollution by heavy metals in mining activities.

In 2022, coal prices had surged in the wake of the war in Ukraine but had subsequently fallen back and have significantly declined since early 2025, when they reached their lowest level in four years.

The price drop has been attributed to the slowing Chinese economy, uncertainties over tariffs and the risk of lower global growth.