Shares in Aterian Plc rose 18% after the company announced an earn-in partnership with Rio Tinto Mining and Kinunga Mining for a lithium project in Rwanda.

Rio has the option to invest up to US$7.5mln to explore and develop lithium, a mineral important for renewable energy.

The investment could give the mining major up to a 75% interest in the project.

The deal also includes an extra payment of US$300,000. The project's location in southern Rwanda is near essential roads, power and water, which makes it attractive for development.

"This is a transformative deal for Aterian and highlights our ability to identify potential world-class deposits in critical minerals such as lithium," said Aterian chairman Charles Bray.  

"We have identified 19 separate LCT (lithium-caesium-tantalum) pegmatite zones across the 2,750-hectare project offering the prospective scale necessary to attract such a major partner as Rio Tinto."

At 9 am, the shares were changing hands for 1.24p, up 0.19p.