(Reuters) - China's Zhaojin Mining Industry has increased its voting power in Tietto Minerals, an exchange filing from the Australian gold miner showed on Friday.

Zhaojin Capital, a unit of Zhaojin Mining, has raised its voting power in Tietto to 23.22% from 16.24%, the filing showed.

Earlier this month, the Chinese gold miner had offered to buy the rest of the shares it does not already own in the Perth-headquartered firm for A$0.68 per share, valuing the gold producer at A$733 million ($478.21 million).

The sweetened bid was Zhaojin Mining's second buyout offer for Tietto Minerals, which has a market capitalisation of $495.5 million, as per LSEG data.

The takeover of Tietto, which already boasts the approval of Australia's foreign investment review board, would see Zhaojin Mining expand its business operations oversees, if it goes through.

($1 = 1.5328 Australian dollars)

(Reporting by Rajasik Mukherjee; Editing by Shilpi Majumdar and Shailesh Kuber)