Canadian exploration company Aldebaran Resources has entered into an option agreement to joint venture with Nuton Holdings, a Rio Tinto venture, on the Altar copper/gold project in Argentina. The Altar project is owned by Peregrine Metals, in which Aldebaran holds a 60% interest, while Sibanye-Stillwater owns the remaining 40%. Aldebaran is currently in the process of acquiring an additional 20% stake, which will increase its holding to 80%, leaving Sibanye-Stillwater with a 20% interest.