Rio Tinto, via its subsidiary with Rio Tinto Mining and Exploration, has signed an earn-in and joint venture (JV) agreement with Raiden Resources in connection with three of Raiden’s exploration licences in Serbia.

The agreement will enable Rio to become a partner in Raiden’s Zapadni Majdanpek, Majdanpek Pojas and Donje Nevlje exploration licences, which are located within the Western Tethyan Metallogenic Belt in Eastern Europe.

The belt is said to host several tier-one copper-gold porphyry and associated mineral deposits.

Rio has the option to invest up to $31.5m over three stages to earn up to a 75% interest in the licences under the agreement.

"In our opinion, this validates the prospectivity of our licences and we look forward to working closely with the Rio team and realising the potential of the JV properties."

Raiden Resources executive director Dusko Ljubojevic said: “Rio Tinto delivers a tremendous depth of experience in these styles of mineralisation and a commitment to the Western Tethyan belt, together with funding capacity to unlock the potential of world class projects.

“In our opinion, this validates the prospectivity of our licences and we look forward to working closely with the Rio team and realising the potential of the JV properties.

“It also enables us to focus on exploration in our retained licences to rapidly deploy our planned exploration programme.”

Rio Tinto is expected to undertake due diligence investigations within 60 days prior to the completion of the deal.

Rio is also required to invest an initial sum of $2.5m over the first three years, which will enable the company to acquire a 51% participating interest in the JV project area.

Thereafter, an additional $9m investment within the subsequent three years will see the company increase its stake by 14%.

In addition, Rio has the option to increase its holding to a total of 75% during the final stage by investing a further $20m over the following three years.

The agreement states that Rio will fund the project until the date it either elects not to proceed with an earn-in stage, the end of the earn-in period or termination of the deal.