Petra Diamonds Ltd. has proposed to offer US$600 million in senior secured second-lien notes due 2022, it said March 30.

The proceeds will be used to refinance the company's existing US$300 million 8.25% senior secured second-lien notes due 2020, to repay all drawn bank facilities and for general corporate purposes.

The company also intends to restructure its debt facilities to US$115 million, from the current total of about US$279 million, in a bid to achieve additional financial flexibility.

Petra's facilities include a 1.25 billion South African rand revolving credit facility, a 900 million rand amortizing term facility, a 700 million rand working capital facility, a US$35 million amortizing term facility and a US$25 million revolving credit facility.

Following the restructuring, which is conditional on the issue of the 2022 notes, the company will hold a 1.00 billion rand revolving credit facility and a 500 million rand working capital facility.

Petra's diamond production in the first half of fiscal 2017 jumped 24% year over year to over 2 million carats, while revenue surged 48% year over year to US$228.5 million on the back of higher sales.