REM, which already has stakes in sizeable lithium prospects in Mexico and the Czech Republic, will pay C$300,000 through a share subscription for a 15.5% stake in Toronto-listed MacArthur Minerals.
MacArthur has applied for ten prospective lithium exploration licences covering 946sq km in the Pilgangoora district, the Eastern Pilbara, and the Mid-West region of Western Australia.
The Eastern Pilbara prospects contain pegmatite deposits similar to those under development by Aussie–listed Pilbara Minerals and Altura Mining.
The largest concentrations of lithium-containing minerals, such as spodumene are found in pegmatites.
Andrew Suckling, REM’s chairman, said: "This strategic investment provides REM exposure to some early stage exploration assets in an area which is prospective for lithium.
“The Pilbara region has rapidly grown and been developing several of high grade hard rock lithium deposits, supplying spodumene concentrate to the lithium carbonate processing plants in China.
“Once granted we look forward to hearing updates on the initial exploration programmes on these applications."
Rare Earth has a 19.8% interest in the Cinovec deposit in the Czech Republic and 17.19% in Bacanora Minerals, the developer of the Sonora lithium deposit in Mexico.