Finsch mine began suspending production this week after business rescue practitioners Daniel van Jaarsveld and Luke Saffy took custodianship of the South African operation.
The halt is an interim step while the practitioners carry out legal rescue requirements and draft a mine-specific business plan for creditors to vote on.
Petra said in May it would place Finsch into business rescue to shield the rest of the group, while arguing the company still has a viable future through Cullinan's distinctive product mix.
The next key decision point is creditor approval of the Finsch plan, which will determine the mine's path forward under rescue proceedings.