Sunstone Metals Ltd. increased its stake in the Bramaderos gold-copper project in Ecuador to 87.5%, the company said Jan. 7.

The project is Sunstone's joint venture with Cornerstone Capital Resources Inc., which now owns a 12.5% stake in the project.

The stake increase was made by amending the terms of the earn-in joint venture, removing Sunstone's requirements to meet various milestones such as funding and completing a feasibility study within five years to achieve an interest of greater than 51%.

The amendment was agreed on as a result of the joint venture agreement phase 2 decision whereby Sunstone could progress to a 70% stake by funding expenditures through to completion of a feasibility study and making a cash payment based on resources defined, or Sunstone to remain at 51% with both parties funding the ongoing exploration.

The company said it will loan-carry Cornerstone's interest through to the start of commercial production. The loan will bear interest at the London interbank offered rate plus 2% and will be repayable out of 90% of Cornerstone's share of future Bramaderos project earnings or dividends.