Clouds cover Atacama salt flat, close to San Pedro de Atacama area during the sunset, Antofagasta region, Chile May 5, 2023. REUTERS/Ivan Alvarado

Mining giant Rio Tinto and Chinese EV-maker BYD are among the six companies eligible to proceed with proposals to develop a lithium project in Chile's Altoandinos salt flats, state-run mining company ENAMI said on Thursday.

The salt flats in the northern region of Atacama are one of the areas where the Chilean government is aiming to boost lithium production in partnership with the state by kicking off new projects.

ENAMI launched its search in May, seeking a partner to offer either financial backing or operational support in Altoandinos, for an ownership stake that has yet to be determined.

The complete list of contenders that can move forward in the process include French miner Eramet, which holds mining concessions at the Altoandinos site, as well as South Korea's LG Energy and Posco, and China's CNGR Advanced Material.

Twelve companies initially expressed interest, ENAMI said last month.

Chile is the world's second-largest producer of lithium, a key material for most batteries that power electric vehicles.

ENAMI is expected to now move into negotiations with the final round of applicants and provide them with technical details about the lithium deposit at Altoandinos.

It aims to formalize a public-private partnership by March 2025, ENAMI said.

"We are moving forward with concrete actions for the National Lithium Strategy, with this announcement of the companies that meet the high selection standards," ENAMI chief Ivan Mlynarz said in a statement.

ENAMI, which processes copper for local mining companies, has been tasked with spearheading the government's maiden ventures into lithium alongside state mining giant Codelco, which is also seeking a partner in the Maricunga salt flat.