According to the company, the offer of $300m secured note is to be issued by the compny’s US subsidiary, and the proceedings from the notes are likely to be used to settle certain existing debt of the company, and towards construction of the processing plant at Cullinan.

The new plant to be constructed at Cullinan mine will require capital of $142.8m, and is expected to improve the recovery of the full spectrum of diamonds along with improvement of the material flow, which will lower the operating costs, according to Petra.

Petra Diamonds CEO Johan Dippenaar said: "In addition to the Notes’ proceeds, Petra’s lender group has agreed in principle to extend and increase the Group’s working capital and debt facilities to approximately US$300 million, which will remain largely undrawn at the time of closing the Notes issue.

"We believe that this new, more diversified, funding package better serves our needs as a business as we continue to grow and evolve and provides additional financial flexibility as we pursue our stated growth strategy."