Tianqi Lithium vowed to continue its battle for a say in a planned deal to share ownership of one of the world’s biggest lithium operations, a case the company sees as crucial for future Chinese investment in Chile.

The Chinese firm, which owns 22% of Chilean miner SQM, is trying to force it to hold a shareholder vote on its partnership with state-owned copper giant Codelco.

Tianqi’s claims are before an appeals court in the South American nation and the outcome is by no means a foregone conclusion, CEO Frank Ha told Bloomberg. He said other options are also available.

“We do not rule out pursuing any legal measures necessary to safeguard the legitimate rights of shareholders,” Ha said in a written response to questions.

In question is a landmark deal that would see SQM relinquish a majority stake in its prized Atacama salt flat mine to Codelco in exchange for three more decades of operations. The tie-up is part of Chilean President Gabriel Boric’s agenda to have more state control of lithium assets.

Chile’s investor-friendly reputation would be tarnished if the deal passed without shareholder approval and greater transparency, according to Tianqi.

“A country with a sound legal system, a good business environment and respect for foreign investors is the cornerstone of our confidence in investing in Chile,” Ha said. If those fundamentals change, “we believe it will not only affect Tianqi, but also Chile’s international image and the long-term development of its industries,” he said.

The Chinese firm’s frustrations appear to be anchored in boardroom restrictions it has endured since paying $4-billion for its SQM stake six years ago. Some of those are set to be lifted by year-end, while others will expire in April, the company said.

SQM, formally known as Soc. Quimica & Minera de Chile, is the world’s second-largest lithium producer. Its top shareholder is Julio Ponce, the former son-in-law of dictator Augusto Pinochet, who ruled Chile in the 1970s and 80s.

While Tianqi hopes it can exercise all of its legitimate rights as SQM’s second-largest shareholder, Ha said the company hasn’t received a positive response from repeated approaches to ministerial departments to undertake more downstream investments in Chile’s lithium industry.

Codelco Chairman Maximo Pacheco said in July that Tianqi’s efforts to force a SQM shareholder vote wouldn’t derail the deal. The two Chilean companies said earlier this month that the transaction is on track to close early next year.