The implied value of the proposal is A$718 million ($487.02 million), comprising A$370 million in cash and 327.1 million Silver Lake shares worth A$348 million.
Taurus Mining Finance Fund No 2 LP has approved a $150 million credit facility for the acquisition and it is subject only to legal due diligence and execution of definitive documentation, Silver Lake said in a statement.
St Barbara has rejected Silver Lake multiple times in favour of a A$600 million proposal from peer Genesis Minerals Ltd.
Last week, gold miner St Barbara said it would not further engage with Silver Lake even after the company raised the cash component of its offer by A$44 million.
St Barbara said Silver Lake's offer was non-binding and "unacceptably conditional" compared to the fully documented, financed and shareholder-backed binding Genesis proposal.
St Barbara Ltd's Leonora assets involved in the deal include the Gwalia underground mine and processing plant, and nearby development opportunities.
In a separate statement, St Barbara said it had received Silver Lake's latest proposal.
Genesis Minerals did not immediately respond to a Reuters' request for comment.
($1 = 1.4743 Australian dollars)
(This story has been refiled to insert dropped word in the headline)
(Reporting by Echha Jain; Editing by Subhranshu Sahu)
