The European Commission has launched a formal investigation inter alia into low airport fees charged by Flughafen Dortmund GmbH to airlines including AirBerlin, easyJet, Germanwings and Wizzair. Flughafen Dortmund GmbH is a publicly owned company that operates the Dortmund airport. In 2004, the company put in place an incentive scheme called NERES (New and Existing Route Expansion Scheme). NERES offers airlines that satisfy its criteria more favourable airport charges than those generally applied and provides these airlines with marketing grants. The Commission considers that NERES may constitute illegal State aid. Investigations on similar and other grounds have also been launched by the Commission against the Luebeck and Berlin Schoenefeld airports in Germany and the Tampere Pirkkala airport in Finland.