Mantena is a Norwegian rolling stock maintenance company owned by Norges Statsbaner (Norwegian State Railways). It has workshops at Grorud and Lodalen in Oslo, Marienborg in Trondheim as well as in Skien, Drammen and Stavanger . In addition to NSB, customers include CargoNet, Kollektivtransportproduksjon, Ofotbanen, Green Cargo, Hector Rail and Tågkompaniet. The company was separated from NSB as a separate limited company in 2002. It has 900 employees and head offices in downtown Oslo. MiTrans, that performs rebuilding of rolling stock, is a wholly owned subsidiary of Mantena.