(Reuters) -Benchmark Mineral Intelligence, a UK-based pricing and data research firm for energy transition minerals, has cut at least a fifth of its workforce in recent weeks, said three people familiar with the company.

The 11-year-old firm had been rapidly expanding over the last couple of years alongside growing market interest in lithium, copper and other minerals needed for electric vehicles and other clean-energy uses.

The layoffs include at least 40 people at Benchmark, the three sources said, out of a total workforce of 200 people. Two of the sources said affected departments included sustainability, sales and marketing. 

CEO Andrew Miller in an email to Reuters said the firm had undergone a "recent restructuring." He declined to comment further on Reuters questions regarding the reductions.

"This process is part of our ongoing efforts to strengthen the quality and delivery of Benchmark's offering, focused around further investment in our technology and AI capabilities," he said.

One source cited weak pricing for minerals, especially battery metal lithium, as a drag on Benchmark's business, whose clients include miners, battery makers and politicians.

Lithium prices have plunged since their peak in 2022 due to slower-than-expected adoption of electric cars.    

In a research note Benchmark published on its website last week, the company said it expected a sharp decline in U.S. EV sales in the last quarter of the year. It added that other challenges such as high manufacturing costs and rising tariffs are prompting some carmakers to scale back EV production plans into next year.

Privately held Benchmark last year bought EV market research firm Rho Motion, creating a combined company of 250 employees. 

In addition to lithium, Benchmark tracks prices and other market data for copper, cobalt, nickel, graphite, rare earths, manganese, fluorspar and phosphate.