In 1908, RWE signed demarcation contracts with Städtische Elektrizitätswerk Dortmund and Elektrizitätswerk Westfalen AG. Together they created Westfälische Verbands-Elektrizitätswerk AG. RWE contributed to the newly established company by its power station in Dortmund–Kruckel and the supply grid in Witten/Dortmund. Later all these companies formed Vereinigte Elektrizitätswerke Westfalen AG (VEW). In 1909, RWE opened the Reisholz Power Plant and acquired a stake in the tram company Süddeutsche Eisenbahngesellschaft AG. At the same year, RWE started to build its own gas supply network. Deliveries of coal gas to the Bergisches Land region started in 1912. In 1914, RWE opened Vorgebirgszentrale power plant in Hürth. By 1920, the plant had installed capacity of 190 megawatts which made it the largest in Europe. Before World War I municipalities of Essen, Mülheim an der Ruhr, and Gelsenkirchen, became shareholders in RWE. By the 1920s, also Bonn, Cologne, Krefeld, Duisburg, and Düsseldorf became shareholders and municipalities owned the majority of RWE's shares. In 1925, Prussian state became a shareholder in RWE. In 1929, municipalities and the Rhine Province combined their shareholdings into a holding company Kommunale Aufnahmegruppe für Aktien GmbH. In 1920, RWE acquired Niedersächsische Kraftwerke AG, located in Osnabrück. In 1922, it expanded its coal business by acquiring three anthracite mines in Essen and a majority stake in the lignite company Braunkohlen- und Briketwerke Roddergrube AG. In 1923, it acquired its founder company EAG. Three year later, the company acquired a stake in Rheinische Elektrizitäts-Aktiengesellschaft (Rheinelektra) and became a shareholder in the newly established Ruhrgas gas company in exchange of its gas grid. In 1927, RWE and Prussia swapped their holdings in the Brunswick and Cologne coalfields and RWE became an owner of Braunkohlen-Industrie AG Zukunft.