Australia's Mineral Resources on Wednesday bought additional shares in lithium miner Azure Minerals to raise its stake to 12.29%, a regulatory filing showed on Friday.
This comes a week after Hancock Prospecting, an iron-ore miner owned by Gina Rinehart, Australia's richest person, built up an 18.3% stake in Azure.
Hancock has previously threatened to torpedoa buyout deal worth A$1.63-billion ($1.05-billion) by Chile's SQM for Azure.
SQM, Azure and MinRes did not immediately respond to a Reuters request for comment.
Minres is constantly scaling up its stake in lithium miners, with the company previously buying shares worth A$158.7-million in Wildcat Resources, bumping up its holding to 19.85%.
Emerging Australian lithium companies are seeing a surge in buyouts as their lower valuations and cash needs attract some of the world's top producers of the battery material and other suitors who are racing to secure supplies.
In October, Albemarle, the world's top lithium chemicals maker, ditched its $4.2-billion bid for Liontown Resources amid "growing complexities", after Hancock popped up on Liontown's register with a 19.9% stake.