An Australian billionaire, Gina Rinehart, increased her share in lithium producer Liontown Resources (LTR.AX) once again, giving her the power to thwart Albemarle Corp.’s (ALB.N) $4.3 billion proposed acquisition of the firm.

According to her firm, Hancock Prospecting, Australia’s richest person, increased her stake to 16.7%, making her Liontown’s greatest stakeholder. “Hancock welcomes the opportunity to participate in the Kathleen Valley project as a shareholder, and have influence on the company’s overall future direction – including where decisions are to be made by shareholders,” the company noted.

One of the most promising lithium resources in the world is Liontown’s Kathleen Valley lithium project in Western Australia. Lithium is a metal used in cell phones and electric cars. The creator has already consented to deliver the basic battery materials to American automaker Ford (F.N).

A spokesman declined to comment on whether Rinehart would use the larger holding to thwart Albemarle’s acquisition attempt. Rinehart has not publicly stated whether she supports or opposes the takeover proposal.

But since early September, when Albemarle (ALB.N), the largest lithium producer in the world, was given access to Liontown’s records after altering an acquisition bid, she has slowly grown her stake in the company.

Regarding the larger Hancock interest, Liontown and Albemarle declined to comment.

Albemarle needs 75% of the votes cast by Liontown shareholders to proceed with its most recent offer of A$3 ($1.91) per share made under a plan of arrangement. Depending on the number of investors present on the day of the shareholder meeting, a stock of between 15% and 20% can frequently constitute a blocking stake. The existing offer cannot be increased, and the bidder must wait a while before coming back with a better offer once Albemarle’s proclaimed its bid to be “best and final.”

The increased Hancock investment was revealed after Australian market trading had concluded, although Liontown’s share price ended up 1% at $A2.99. The stock had increased since the last Albemarle bid surfaced in early September, trading at about A$2.62. After September 11th, Albemarle was given four weeks of due diligence; according to local media accounts, that access was set to end on Friday.

In October of last year, the American company offered $A2.20 per share for Liontown before sweetening its offer to $A2.35 and then $A2.50, which were turned down by the target company’s board in March. At Liontown’s approaching annual public meeting in November, Hancock indicated it had no intentions to nominate directors. Still, it remained open to doing so later on, particularly “if its strategic stake continues to increase towards 19.9%,” the business stated in a statement.

If Hancock’s share rises over 19.9%, it must disclose its plans for its investment in Liontown. Hancock now owns 14.97% of the miner, taking over for Liontown Chairman Tim Goyder, previously the company’s largest stakeholder.