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 (approximately IDR 3.82 trillion, based on an exchange rate of IDR 17,775 per USD). This divestment is one of three major transactions announced in December 2025, reflecting Harbour’s ongoing efforts to streamline its portfolio and reallocate resources toward its most competitive opportunities.
Steve Cox, Managing Director of Harbour’s business unit in Indonesia, described the sale of these primary Indonesian assets as a strategic milestone for the company. “This move demonstrates 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 future endeavors,” Cox stated in an official release on Friday (May 29, 2026).
Prior to this transaction, Harbour served as the operator for both assets, holding a 28.67% participating interest in the producing Natuna Block A and a 50% stake in the development-stage Tuna Block.
While the sale marks a significant shift in its local operations, Harbour Energy is not fully exiting the Indonesian market. The company remains committed to its exploration projects in the Andaman Sea. Currently, Harbour retains a 40% operating interest in the Andaman II Block and an 80% stake in the Central Andaman Block. Additionally, it remains involved in the development of the South Andaman Block alongside Mubadala Energy, holding a 20% non-operating interest.
The decision to divest from the Tuna Block was largely driven by the company’s inability to move forward with development due to Western sanctions imposed on its Russian partner. Harbour, through Premier Oil Tuna B.V., had been partnered with ZN Asia Ltd.—a subsidiary of the Russian state-owned enterprise Zarubezhneft—which also held a 50% stake in the project.
Despite the challenges, the Tuna Block is set for a restart. Following a meeting in Kazan, Russia, on May 12, 2026, Indonesia’s Deputy Minister of Energy and Mineral Resources, Yuliot, confirmed that Zarubezhneft intends to resume development in June 2026.
“We met with Zarubezhneft to discuss the progress of the stalled Tuna Block project. They have expressed their firm commitment to resume operations next June, and the government is fully prepared to provide the necessary support to ensure the project’s continuity,” Yuliot stated.
Zarubezhneft has been an active player in Indonesia’s oil and gas sector since 2020, when it acquired its 50% participating interest in the Tuna Project through its subsidiary, ZN Asia Ltd.
Summary
Harbour Energy has finalized the divestment of its interests in the Natuna Sea Block A and the Tuna Block to Prime Group for US$215 million. This strategic move aligns with the company’s objective to streamline its global portfolio and reallocate resources toward more competitive assets. While Harbour is exiting these specific projects, it remains active in Indonesia through its ongoing exploration and development interests in the Andaman Sea.
The divestment of the Tuna Block was primarily necessitated by development delays resulting from Western sanctions on Harbour’s Russian partner, ZN Asia Ltd. Despite these previous complications, the Indonesian government has confirmed that the Russian state-owned firm, Zarubezhneft, intends to resume development of the Tuna project in June 2026. Authorities have pledged their support to ensure the successful restart and continuity of operations at the site.
