Two of the top traders in Glencore’s aluminum department are leaving for Vitol Group and Mercuria Energy Group  — the latest sign of how a return into metals by energy firms is fueling a talent war in the sector.

Sam Imfeld, a longstanding trader in Glencore’s aluminum and alumina team, will be joining Vitol in Singapore, according to people familiar with the matter. Meanwhile alumina trader Steven Rojas will join Mercuria later this year. They both worked under Robin Scheiner, Glencore’s head of alumina and aluminum trading.

The moves are the latest signs that Glencore and Trafigura Group, which have long dominated metals trading, are being challenged by an influx of new competition. Mercuria, Vitol and Gunvor Group are staffing up sizable teams in aluminum, copper and iron ore as they look to generate revenues outside of energy markets that have been extremely lucrative since Russia’s invasion of Ukraine.

Last year, Vitol poached several members of Glencore’s iron ore team, while Mercuria has aggressively hired about 40 staff in metals in a few months.

The exits come after Jason Kluk, Glencore’s head of nickel and ferroalloy trading, left the company in November.

Mercuria and Vitol’s hires come after alumina prices surged to a record on the back of a scramble for supplies after export restrictions from leading bauxite miner Guinea. While prices have slid 16% from a record high of $805.83 a ton in December, they remain elevated relative to aluminum prices, hurting traders that often have long-term contracts to supply alumina at prices linked to the price of aluminum.

Aluminum has historically been a major trading book for Glencore, fueled by offtake agreements with Century Aluminum Co. and Russia’s United Co. Rusal International PJSC — long the market’s biggest contract. In 2023 it expanded upstream with a $1.1-billion deal to buy alumina and bauxite assets in Brazil.

Glencore was for many years the clear leader in metals trading, boasting in its 2011 IPO prospectus that it handled 50% or more of the “addressable” markets for some metals. But more recently Trafigura has drawn level with or surpassed it in key markets including copper.

Glencore, Mercuria and Vitol declined to comment.