Olusola Bello
Nigeria has secured a major victory in its long-running international arbitration dispute with Sunrise Power and Transmission Company Limited after an International Chamber of Commerce (ICC) tribunal in Paris rejected claims linked to the stalled Mambilla Hydroelectric Power Project in Taraba State.
The tribunal issued its award on September 17, 2026, rejecting Sunrise Power’s claims against the Federal Government of Nigeria and in proceedings involving its promoter, Leno Adesanya.
The related claims had exposed Nigeria to potential liabilities of more than $3.38 billion. They included a $680 million claim for a settlement sum and interest, as well as a separate claim of more than $2.7 billion in compensation and interest arising from disputes over the development of the Mambilla project.
President Bola Tinubu described the ruling as a major breakthrough for the project, saying it had removed what he regarded as the biggest legal obstacle that had prevented the Mambilla scheme from progressing for years.
“Today’s ICC ruling clears the single biggest legal hurdle that has paralysed the Mambilla hydro power project for years,” Tinubu said in a statement issued on Thursday.
Dispute dates back to 2003 contract
The arbitration has its roots in a 2003 agreement under which Sunrise was to develop a large hydropower plant in Taraba State under a build-operate-transfer arrangement.
The original proposal envisaged a 3,050-megawatt facility. The Federal Government subsequently revised the project scope, with the planned capacity later reduced to about 1,500MW as efforts continued to make the project financially viable and bankable.
The legality and authorisation of the original 2003 agreement became a central issue in the dispute.
According to the Presidency, the Federal Executive Council did not authorise the contract. Former Presidents Olusegun Obasanjo and the late Muhammadu Buhari also testified in proceedings relating to the dispute.
Sunrise subsequently commenced arbitration proceedings against Nigeria at the ICC in 2017.
The dispute later generated a second arbitration following a 2020 settlement arrangement. Reports on the final award indicate that the tribunal rejected Sunrise’s claim that Nigeria had breached its obligations under the settlement agreement and its addendum. It also rejected a demand for payment of $400 million arising from the settlement and alleged default.
Tribunal ruling reduces financial exposure
The ruling is significant for Nigeria because of the size of the claims involved.
The combined potential exposure from the related proceedings was estimated at more than $3.38 billion. The tribunal’s decision therefore removes a major contingent liability associated with the Mambilla dispute.
Reports on the award also indicate that Sunrise Power and Adesanya were ordered to bear a substantial portion of Nigeria’s legal costs. One account put the amount at about $11.82 million, with the tribunal allocating 75 per cent of the costs against Sunrise and Adesanya.
The tribunal also determined that Adesanya was bound by the relevant arbitration agreement and that it had jurisdiction over Nigeria’s counterclaim against him and his company.
Tinubu commends legal team
Reacting to the decision, President Tinubu commended Attorney-General of the Federation and Minister of Justice, Lateef Fagbemi, and officials of the Federal Ministry of Justice for their role in Nigeria’s defence.
He also praised Nigeria’s external legal team, led by Elizabeth Oger-Gross and Tolu Obamuroh of Paul Hastings LLP.
Tinubu acknowledged the contributions of former Presidents Obasanjo and Buhari, who testified during the proceedings, as well as former Ministers of Power Babatunde Fashola and Suleiman Adamu and other witnesses and experts.
He also commended the National Security Adviser and the Economic and Financial Crimes Commission for their roles in the broader matter.
The President said the outcome demonstrated the government’s commitment to defending Nigeria’s legal and financial interests while continuing to work with legitimate investors.
What the ruling means for Mambilla
The immediate significance of the ICC award is that it removes a major legal dispute surrounding one of Nigeria’s most ambitious power projects.
The Mambilla Hydroelectric Power Project has been planned for decades but has faced contractual disputes, financing challenges and other obstacles.
The project is strategically important because Nigeria continues to struggle with inadequate electricity generation and transmission capacity, while hydropower remains one of the country’s major sources of large-scale renewable electricity.
However, the ICC ruling does not by itself deliver the project.
Nigeria will still need to address the project’s financing, construction structure, transmission infrastructure, implementation timetable and overall bankability before the scheme can translate from a long-running development proposal into additional electricity supply.
The government will therefore face the task of converting the legal breakthrough into a credible investment and construction framework.
For international investors, the decision also provides a significant development in assessing the legal environment surrounding major infrastructure projects in Nigeria.
Tinubu said Nigeria remained committed to genuine investors and to honouring its legal obligations, while defending what his administration considers unfounded claims against the country’s assets.
The President’s statement described the Sunrise claims as “opportunistic” and said the government would continue to defend the national interest through legal and institutional channels.
With the ICC dispute now decided in Nigeria’s favour, attention is expected to shift from arbitration to the more difficult question of whether the Mambilla project can finally secure the financing, contractual structure and execution framework required to move construction forward.