Nigeria has secured a major legal victory in the long-running dispute surrounding the Mambilla Hydroelectric Power Project after an International Chamber of Commerce (ICC) arbitration tribunal in Paris ruled in favour of the Federal Government.
The ruling effectively removes a major legal obstacle that had threatened to further delay the long-awaited power project and could have exposed Nigeria to claims exceeding $3.38 billion.
The arbitration decision was issued on September 17, 2026, after almost nine years of legal proceedings between the Federal Government and Sunrise Power and Transmission Company Limited, which had pursued claims connected to agreements concerning the development of the Mambilla project in Taraba State.
President Bola Tinubu described the judgment as a significant development, saying the ICC decision had cleared what he called the biggest legal hurdle that had paralysed the Mambilla hydroelectric project for years.
The dispute dates back to October 2017, when Sunrise Power commenced arbitration proceedings against Nigeria at the ICC International Court of Arbitration.
The company pursued claims arising from an earlier agreement concerning the development of the Mambilla power project and subsequently sought substantial compensation and interest.
According to the Presidency, one of the related claims involved a demand of about $680 million, while another arbitration connected to the project involved claims exceeding $2.7 billion in compensation and interest.
Together, the claims placed Nigeria’s potential financial exposure at more than $3.38 billion.
The tribunal rejected Sunrise Power’s claims in the latest arbitration.
The decision also rejected the company’s request for an order compelling Nigeria to pay a $200 million settlement sum and a further $200 million default payment.
The tribunal further determined that Leno Adesanya, the promoter of Sunrise Power, was bound by the arbitration provisions contained in the relevant settlement agreement and addendum.
Beyond dismissing Sunrise Power’s claims, the tribunal ordered the company and Adesanya to reimburse Nigeria for 75 per cent of the legal fees and expenses incurred in defending the arbitration.
Nigeria’s recoverable legal costs were put at approximately $11.82 million.
About $2.5 million is expected to be released from funds held in escrow by the ICC, while the remaining amount is to be paid by Sunrise Power and Adesanya, with interest applying until payment is completed.
The arbitration costs were also fixed at approximately $1.66 million, with Sunrise Power and Adesanya responsible for 75 per cent and Nigeria responsible for the remaining 25 per cent.
The Nigerian defence team was led by Elizabeth Oger-Gross and Tolu Obamuroh of Paul Hastings LLP.
Reacting to the ruling, President Tinubu said the judgment had removed the major legal impediment standing in the way of the project.
“Today’s ICC ruling clears the single biggest legal hurdle that has paralysed the Mambilla hydro power project for years,” the President said.
Tinubu commended Attorney-General of the Federation and Minister of Justice, Lateef Fagbemi, and officials of the Federal Ministry of Justice for their handling of the arbitration.
He also praised members of Nigeria’s legal defence team and acknowledged the participation of former President Olusegun Obasanjo and the late former President Muhammadu Buhari, who appeared as witnesses during the proceedings.
Former ministers Babatunde Fashola and Suleiman Adamu were also acknowledged for their roles as witnesses, alongside other experts involved in Nigeria’s defence.
The Mambilla Hydroelectric Power Project has been under consideration for more than two decades and has passed through several stages of restructuring, legal disputes and financing challenges.
The original proposal envisaged a much larger hydroelectric development in Taraba State.
The Federal Government subsequently revised the project’s scope and capacity as part of efforts to make the investment financially viable and attractive to lenders.
Earlier plans placed the project at about 3,050MW, while subsequent government plans reduced the proposed capacity to around 1,525MW before it was later rescoped to approximately 1,500MW.
The reduction was linked to efforts to lower the project’s cost and improve its financial viability.
The Mambilla project has repeatedly been identified by successive Nigerian governments as an important component of efforts to expand the country’s electricity generation capacity.
However, its implementation has been slowed by legal disputes, financing difficulties and changes to the project’s structure.
The proposed Mambilla hydropower development is expected to add significant generation capacity to Nigeria’s electricity system if completed.
Its long delay has made it one of the country’s most prominent unfinished power infrastructure projects.
The latest arbitration victory does not itself mean that construction will immediately begin. Financing, contractual arrangements, project restructuring and other implementation requirements still have to be addressed.
However, the Federal Government now faces fewer legal complications associated with the Sunrise Power dispute.
The State House described the ruling as removing a major obstacle that had hindered progress on the project.
Tinubu said the government remained committed to working with legitimate investors and fulfilling its lawful contractual obligations.
At the same time, he said Nigeria would continue to defend itself against claims it considers unjustified.
The President also commended the National Security Adviser for supporting the government’s case and the Economic and Financial Crimes Commission for its investigation into aspects of the dispute.
The Mambilla ruling adds to a series of major international arbitration disputes involving Nigeria.
The latest judgment means the country has avoided the potentially enormous financial liability associated with the Sunrise Power claims, while the Federal Government can now focus more directly on resolving the remaining financing and implementation challenges surrounding the long-delayed Mambilla hydropower project.
For Nigeria’s electricity sector, the significance of the development will ultimately depend on whether the legal breakthrough is followed by concrete steps to secure financing and move the approximately 1,500MW Mambilla project from years of planning and litigation towards actual construction.
