Automakers around the world have been engaged in a race to secure the critical minerals for electric vehicles (EV) with a number of companies inking deals with mining companies. Tesla, one of the leading EV producers in the world, is reported to have been in talks to go one more step and purchase 10 to 20 percent of a mining company, Swiss commodities group, Glencore.

The Financial Times reported that the talks began in 2021 and continued in 2022 when Glencore chief executive Gary Nagle visited Tesla’s factory in Fremont, CA, as part of a roadshow for the mining company’s annual results.

According to people familiar with the discussion a deal was not reached because Tesla had concerns over whether Glencore’s extensive coal mining business was compatible with the carmaker’s environmental goals, and was reluctant to take a minority equity stake.

Glencore is the world’s largest listed trading house and biggest producer of cobalt through its mines in the Democratic Republic of Congo, Australia and Canada. Two years ago, Tesla secured a cobalt offtake agreement with the Swiss group to supply its factories in Shanghai and Berlin. Tesla founder Elon Musk has previously outlined Tesla’s intention to take greater control of all manufacturing steps of its batteries, including processing the raw materials and even buying lithium deposits still in the ground, if the supply chain fails to deliver.

In April, the billionaire took to Twitter, the social media site he bought this week, to voice his concerns about lithium costs: “Tesla might actually have to get into the mining & refining directly at scale, unless costs improve.”

The price of lithium has risen eightfold since the start of 2021. Tesla is also advancing with plans to build its own lithium hydroxide refinery on the Texas Gulf Coast.

Glencore produces cobalt, nickel, copper and other minerals, and is also one of the world’s largest recyclers of batteries. It does not mine lithium but recently started to trade the metal.

Glencore already has cobalt offtake agreements with battery makers SK Innovation and Samsung SDI, and carmakers BMW and General Motors. As well as its cobalt offtake agreement with Glencore, Tesla has struck a long-term deal for nickel supply from Brazilian mining group Vale.

Ford has a lithium offtake agreement with Australia-based Liontown Resources that includes stumping up financing for the project upfront, and has taken a minority stake in a nickel ore processing plant in Indonesia.