Thomassen Nigeria Ltd was established in Lagos, Nigeria. The primary business focus is to provide technical O&M services to Power Plants in Nigeria and Africa region.

Thomassen is founding shareholder in Transcorp Ughelli Power Limited, Nigeria, and participated successfully in the 1st round of privatisation of the 935MW Ughelli Power Plant in Delta State consisting of 6x F9E and 12x H25. Since 2012, Thomassen has been the technical and O&M partner of the Ughelli Power Plant.