Nigeria Defeats $3.38bn Mambilla Claims As ICC Ruling Clears Legal Obstacle

By Sabiu Abdullahi

Nigeria has secured a major victory in the long-running arbitration dispute with Sunrise Power and Transmission Company Limited over the Mambilla Hydroelectric Power Project in Taraba State.

An International Chamber of Commerce (ICC) arbitration tribunal in Paris, France, issued its final award on September 17, 2026, rejecting Sunrise Power’s claims against the Federal Government. The related claims had exposed Nigeria to potential liabilities of more than $3.38 billion.

President Bola Tinubu confirmed the ruling in a statement on Thursday. He said the decision had removed a major legal obstacle to the long-delayed power project.

“Today’s ICC ruling clears the single biggest legal hurdle that has paralysed the Mambilla hydro power project for years,” the President said.

The dispute dates back to 2003, when an agreement was reached for the development of a 3,050-megawatt hydroelectric plant in Taraba State under a build-operate-transfer arrangement.

Sunrise commenced arbitration proceedings against Nigeria at the ICC International Court of Arbitration on October 10, 2017. The company sought about $2.35 billion over what it described as a breach of contractual obligations.

A separate dispute later emerged from a 2020 settlement agreement. Sunrise sought $400 million, comprising a $200 million settlement sum and an additional $200 million default payment. The Presidency said the company also had a separate claim for more than $2.7 billion in compensation and interest, bringing the potential exposure from the related claims above $3.38 billion.

Tribunal Rejects Sunrise’s Claims

Details of the award show that the three-member tribunal rejected Sunrise’s request for a declaration that Nigeria had breached its obligations under the settlement agreement and its addendum.

The panel also dismissed the company’s demand for the $400 million settlement and default payments.

The tribunal further held that Leno Adesanya, the promoter of Sunrise Power, was bound by the arbitration agreement under the settlement arrangement and its addendum.

It also ruled that it had jurisdiction over Nigeria’s counterclaim against Adesanya and Sunrise.

The tribunal ordered Sunrise and Adesanya to reimburse Nigeria for 75 per cent of the legal fees and expenses incurred during the arbitration.

Nigeria’s legal fees were put at about $11.82 million. Of that amount, $2.5 million is expected to come from funds held in escrow by the ICC, while Sunrise and Adesanya are to pay the remaining $9.32 million.

The outstanding amount will attract 10 per cent annual interest, compounded annually, from notification of the final award until full payment. The tribunal also fixed the arbitration costs at about $1.66 million, with Sunrise and Adesanya responsible for 75 per cent and Nigeria for the remaining 25 per cent.

The tribunal was chaired by Melaine van Leeuwen, with Stavros Brekoulakis and Simon Nesbitt as co-arbitrators.

Nigeria’s defence team was led by Elizabeth Oger-Gross and Tolu Obamuroh of Paul Hastings LLP.

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 the case.

He also praised the lawyers who represented Nigeria.

“This latest decision affirms the Nigerian State’s determination not to succumb to predatory and exploitative claims by corrupt local and international entities and their enablers and funders,” Tinubu said.

Tinubu Praises Obasanjo, Buhari

The President also commended former President Olusegun Obasanjo and the late former President Muhammadu Buhari for their participation in the arbitration proceedings.

Both former presidents testified in Nigeria’s defence.

“I commend the patriotism and support of former President Olusegun Obasanjo, GCFR, and late President Muhammadu Buhari, GCFR, who testified in the case, which dated back to an illegal 2003 contract to build a 3,050-megawatt hydroelectric plant in Taraba State under a build-operate-transfer model. The Federal Executive Council never authorised the contract,” he said.

Tinubu also recognised former ministers Babatunde Fashola and Suleiman Adamu, as well as other witnesses and experts who took part in Nigeria’s defence.

He further commended the National Security Adviser for supporting the government’s position and the Economic and Financial Crimes Commission for its investigation into the matter.

The President said the government remained open to legitimate investment while maintaining that Nigeria would defend its interests against claims it considers unjustified.

“I want to assure you that while our country remains committed to partnering with genuine investors and honouring its legal obligations, it will continue to defend all opportunistic claims instituted against our commonwealth strongly,” the President said.

Mambilla Project Faces Long Delay

The Mambilla project has remained largely uncompleted despite its identification by successive administrations as a major addition to Nigeria’s electricity generation capacity.

The original proposal was for a 3,050MW facility. The Federal Government later reduced the planned capacity to about 1,525MW and subsequently rescaled it to approximately 1,500MW in an effort to improve its financial viability and make it “bankable” for lenders.

The project has faced several obstacles, including legal disputes, financing difficulties and changes to its implementation arrangements.

The parties had attempted to settle their dispute in 2020, but disagreements over the implementation of the settlement eventually resulted in another arbitration.

The latest ICC decision has therefore removed a major legal dispute surrounding the project, although the project still faces financing and implementation issues before construction can move forward.

Nigeria’s victory in the case comes after other major international disputes involving the Federal Government. In 2023, a UK court set aside an $11 billion arbitration award against Nigeria in the case involving Process & Industrial Developments Limited over a failed gas processing agreement.

The Mambilla project has also featured in investigations and court proceedings involving former officials of the power sector, while questions over financing and policy continuity have continued to affect major electricity projects in the country.