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May 1 (Reuters) - China's Zhaojin Capital, a unit of gold miner Zhaojin Mining Industry 1818.HK , has raised its stake in its Australian takeover target Tietto Minerals (TIE) to 52.8%, an exchange filing showed on Wednesday.

The exchange filing showed that Zhaojin Capital voting power was now at 52.8% from 42.5% earlier.

The stake increase comes a day after the Perth-headquartered gold miner called upon its shareholders to accept Zhaojin's takeover bid that valued the company at A$733 million ($474.62 million).

Tietto also urged shareholders to sell their stake in the company on-market "if the market price is not materially different to the offer price."

Tietto had indicated in its last press release that two of its major shareholders might have accepted the Chinese suitor's offer after a significant jump in the latter's voting power to more than 42% as of April 29.

Zhaojin declared its bid to be unconditional on April 24, making it impossible for Tietto shareholders - who had already accepted the offer - to now withdraw their acceptance.

If the deal goes through, the takeover would help Zhaojin Mining expand its business operations overseas. Tietto has already received approval from Australia's Foreign Investment Review Board.

($1 = 1.5444 Australian dollars)