China's private energy company Shanxi Donghui Coal Coking & Chemicals Group Co Ltd plans to make an off-market takeover bid to acquire all the ordinary shares in Inova Resources Ltd for $160 million.

Inova Resources, the Australian-based copper and gold miner, is controlled by the world mining giant Rio Tinto's Turquoise Hill Resources Ltd.

Shanxi Donghui's offer is for AUD$0.22 cash per Inova share, the company said on Wednesday.

According to public informa-tion, the mining giant has been considering selling the assets since a year ago.

Shanxi Donghui's offer provides Inova shareholders with certainty of value at an attractive, risk-free, cash premium for their investment, said the company.

Inova's largest shareholder, Turquoise Hill Resources, has entered into a pre-bid acceptance agreement for 14.9 percent of Inova.

"Shanxi Donghui looks forward to progressing the development of Inova's mines and growth projects and managing the inherent risks involved. We believe our offer provides Inova shareholders with a full and fair risk-free cash premium for their investment," said Zhang Yaping, chairman of Shanxi Donghui.