JAKARTA – Harbour Energy has officially finalized the sale of its participating interests in the Natuna Sea Block A and the Tuna Block to Prime Group for US$215 million, equivalent to approximately Rp3.82 trillion (based on an exchange rate of Rp17,775 per US$).
This divestment is one of three major transactions announced in December 2025. The move serves as part of Harbour’s ongoing strategic effort to streamline its global portfolio and focus capital resources on its most competitive assets. Steve Cox, Managing Director of Harbour’s Indonesian business unit, noted that the sale represents a significant milestone in the company’s corporate strategy.
“This reflects our disciplined approach to portfolio management, following our exit from Vietnam last year. I am deeply grateful to our colleagues in Indonesia for their hard work on these assets over the years and wish them the very best in their next chapter,” said Cox in an official statement released on Friday (May 29, 2026).
Prior to the sale, Harbour served as the operator for both fields, holding a 28.67% interest in the producing Natuna Block A and a 50% stake in the Tuna Block, which is currently in the development phase. While this divestment concludes their tenure at these specific sites, Harbour maintains a robust presence in Indonesia through its continued focus on exploration and development in the Andaman Sea.
Harbour currently holds a 40% operating stake in the Andaman II block and an 80% stake in the Central Andaman block. Additionally, the company remains a partner in the South Andaman block, holding a 20% non-operating interest alongside Mubadala Energy.
The decision to exit the Tuna Block was largely driven by the complexities of international development, specifically the impact of Western sanctions on Harbour’s Russian partner, ZN Asia Ltd—a subsidiary of the Russian state-owned enterprise Zarubezhneft—which held the remaining 50% interest in the project. These geopolitical constraints had previously stalled progress on the field.
However, the project is now set to move forward. Zarubezhneft is expected to resume development of the Tuna Block starting in June 2026. This commitment was confirmed by the Deputy Minister of Energy and Mineral Resources, Yuliot, following a meeting with the Russian oil and gas company during the 14th Indonesia–Russia Joint Commission Session on Trade, Economic, and Technical Cooperation in Kazan, Russia, on May 12, 2026.
“We met with Zarubezhneft to discuss the resumption of the delayed Tuna Block project. They have expressed their commitment to restarting operations next month. The government is prepared to provide full support to ensure this project continues smoothly,” Yuliot stated. Zarubezhneft first entered the Indonesian market in 2020 through the acquisition of its 50% participating interest in the Tuna project.
Summary
Harbour Energy has finalized the sale of its interests in the Natuna Sea Block A and the Tuna Block to Prime Group for US$215 million. This divestment is part of the company’s broader strategic initiative to streamline its global portfolio and focus on more competitive assets. Despite exiting these fields, Harbour Energy maintains a significant presence in Indonesia, particularly through its ongoing exploration and development projects in the Andaman Sea.
The decision to divest from the Tuna Block was largely influenced by geopolitical complexities involving international sanctions against Harbour’s former partner, ZN Asia Ltd. Following the sale, Zarubezhneft is now expected to resume development of the Tuna Block in June 2026. The Indonesian government has pledged its full support to ensure the project moves forward effectively under its new operational phase.