UPDATE 2pm: Straits Resources says it has banked the $27 million from the sale of its Hillgrove Antimony gold mine to Bracken Resources.

Managing director Andre Labuschagne said the sale was another significant step in the process of simplifying the company's structure as it progressed towards the demerger of the copper and gold businesses.

Straits, which owns the Tritton copper mine in NSW and the Mt Muro gold operation in Indonesia, has struggled with spiralling costs at both mines in recent times.