SANTIAGO - Chinese lithium miner Tianqi has appealed a ruling by Chilean financial regulator CMF that shareholder approval is not needed to proceed with a major tie-up set to boost state control over the country's lithium sector, it said on Saturday.

Tianqi has repeatedly called for the planned partnership between state miner Codelco and SQM, the world's No. 2 lithium producer, to be put to a shareholders' vote. Tianqi owns about a fifth of SQM.

The partnership would grant SQM the ability to extract lithium in the prized Atacama salt flat through 2060, while giving Codelco, the copper miner, a major role in the lithium industry in Chile, the world's second-biggest supplier of the key battery metal after Australia.

The Chinese firm said in a statement it had made a formal request to Santiago's Court of Appeals. It asked that the CMF ruling be suspended until a final resolution is reached, an action that could halt the deal from moving forward.

SQM and Codelco predicted that final regulatory approvals will come in the first few months of 2025 and plan to begin the partnership the same year.

"The CMF ruling we are appealing represents not just one particular case, but implies negative influences for future operations," Tianqi said, adding it would continue to take "all legal measures necessary" to defend its interests.

"The events surrounding the Codelco-SQM deal sets a major precedent of great gravity that has throughout the process exposed a lack of the most minimal transparency standards and respect for the rights of minority shareholders," it added.

The SQM-Codelco deal was finalised in May and Tianqi had until Saturday to file the appeal.

CMF made the ruling in June, saying the decision was not appropriate for a shareholder vote and should instead be resolved by SQM's board of directors.

Though companies have scrambled for control over the metal used to build batteries fueling electric vehicles, prices that rose rapidly through 2022 have since slumped over a supply glut and weaker-than-expected demand.