ICC tribunal rules in Nigeria’s favour, rejects $3.38 billion Mambilla claim

An International Arbitration Tribunal under the auspices of the International Chamber of Commerce (ICC) in Paris has ruled in favour of Nigeria, rejecting claims by Sunrise Power and Transmission Company Ltd (Sunrise) with a combined value of about $3.38 billion in disputes linked to the Mambilla Hydroelectric Power Project in Taraba State.

President Bola Ahmed Tinubu disclosed the development in a statement on Thursday, September 17, 2026, following the issuance of the tribunal’s award.

The claims comprised a $680 million demand for a settlement sum and interest and a separate claim of more than $2.7 billion in compensation and interest relating to disputes over the development of the Mambilla project.

The two related claims represented a potential financial exposure of more than $3.38 billion for Nigeria.

What they are saying

President Tinubu said the ruling reinforces the Nigerian government’s position that it will defend the country against claims it considers detrimental to the national interest, while maintaining that Nigeria remains committed to working with legitimate investors and meeting its legal obligations.

• “The company had made a claim against the Federal Republic of Nigeria, demanding $680 million as a settlement sum and interest in respect of another arbitration in which it is claiming over $2.7 billion in compensation and interest relating to disputes associated with the development of the 3960mw Mambila Hydroelectric Power Project, located in Taraba State.”

Tinubu also credited members of Nigeria’s legal and government teams, including Attorney-General of the Federation and Minister of Justice Lateef Fagbemi, the Federal Ministry of Justice and Nigeria’s external defence counsel, Elizabeth Oger-Gross and Tolu Obamuroh of Paul Hastings LLP.

The President also acknowledged former President Olusegun Obasanjo and the late former President Muhammadu Buhari, who testified in the arbitration, as well as former Ministers of Power Babatunde Fashola and Suleiman Adamu and other witnesses and experts involved in Nigeria’s defence.

Back story

The Mambilla Hydroelectric Power Project has been in development for decades and has been the subject of contractual, financial and legal disputes.

• In 2003, the then Minister of Power and Steel, Olu Agunloye, awarded Sunrise Power a build-operate-transfer contract for the development of a 3,050MW Mambilla hydropower plant at an estimated cost of about $6 billion. The agreement envisaged Sunrise financing and developing the project and recovering its investment from electricity sales over a long-term period.
• The legality of the award later became a central issue in the dispute. In court proceedings in 2025, an EFCC investigator testified that former President Obasanjo and the Federal Executive Council had not approved the contract and that Agunloye awarded it on May 22, 2003, shortly after an FEC meeting at which the proposal was reportedly withdrawn. Agunloye has pleaded not guilty to the criminal charges arising from the matter.
• Sunrise subsequently commenced arbitration against Nigeria at the ICC on October 10, 2017, seeking about $2.354 billion over an alleged breach of the 2003 agreement.

A settlement was later negotiated under which Nigeria agreed to pay Sunrise $200 million. The agreement also provided for a 10% penalty in the event of default. Sunrise later filed another $400 million claim related to the settlement, which rose to about $680 million with interest.

• The September 17, 2026 ICC ruling has now rejected the related claims, removing a combined potential exposure of more than $3.38 billion.
• The dispute has also generated separate domestic legal proceedings. In December 2023, the EFCC declared former Minister Olu Agunloye wanted over alleged fraud connected to the $6 billion Mambilla contract.

In September 2024, the Federal High Court in Abuja ordered the EFCC to remove Sunrise promoter Leno Adesanya from its wanted list in connection with allegations linked to the Mambilla project. However, the Court of Appeal later stayed execution of that judgment pending the determination of the Federal Government’s appeal.

What you should know

The Mambilla ruling adds to a series of major legal victories Nigeria has recorded in recent years in disputes involving substantial financial claims.

• In October 2023, the Commercial Court in London set aside arbitration awards against Nigeria in the case involving Process & Industrial Developments (P&ID). The awards, originally worth $6.6 billion plus interest and exceeding $11 billion by the time of the UK proceedings, had arisen from a failed gas processing agreement. The court found that the awards had been obtained by fraud and that the manner in which they were procured was contrary to public policy.
• In November 2025, Nigeria also secured a favourable arbitral award in a long-running dispute over civil works at the Ajaokuta Steel Complex. A tribunal constituted under the Alternative Dispute Resolution Centre of the Federal High Court dismissed claims by Fougerolle Nigeria Ltd and Fougerolle SA amounting to about N4 billion and €185.7 million.

More recently, in February 2026, Nigeria won an arbitration dispute against European Dynamics UK Ltd over a national electronic government procurement project. The tribunal dismissed all of the company’s claims, which totalled about $6.2 million, according to the Attorney-General’s office.