Albemarle says it wants to take control of Australia's Greenbushes, the world's largest lithium mine, signaling it intends to block any rival from buying Tianqi Lithium Corp's controlling stake.

Tianqi, which owns 51% of Greenbushes to Albemarle's 49%, is selling some of its prized assets, including Greenbushes, to pay down debt.

While Albemarle said earlier this month that it was interested in the sale, Thursday's comments were the strongest to date that the company intends to exercise its right of first refusal to supersede other potential buyers.

"We would be interested in taking a controlling stake in that venture," Eric Norris, head of Albemarle's lithium division, said in a webcast of Benchmark Mineral Intelligence's EV Supply Chain Festival. "We will keep our position and would like to increase it."

Lithium, used to make electric vehicle batteries, is most commonly found in brine and hard rock. Albemarle already operates in Chile's Atacama desert, the world's largest source of lithium from brine.

By taking over Greenbushes, a hard rock mine, Albemarle would gain control over another cheap source of the white metal, one that Norris described as the "world's best resource."

Tianqi's financial troubles come amid a rough patch for the lithium industry, which is contending with oversupply and the coronavirus pandemic, factors that have paused the electric-vehicle revolution.

Tianqi said last week its controlling shareholder planned to sell around a sixth of its holding, which could raise more than $200-million.

Tianqi also said it has been talking to banks about easing the terms of its debt, which includes a $3.5-billion loan to buy a stake in Chilean miner SQM - Albemarle's biggest rival - two years ago.

"My hunch is there's going to be a path out of this for Tianqi that works," Norris told the Thursday conference.