A renaissance for night trains in Europe is one step closer after rail companies in four countries signed a cooperation pact Tuesday to revive a Paris-Vienna service in a year. The deal between Austria's OBB, France's SNCF, Germany's Deutsche Bahn and Switzerland's CFF, signed on the margins of a meeting of EU transport ministers, aims to have the service running by December 2021. Tuesday's agreement was aimed at resolving problems that have held back relaunching night services and ensure better commercial cooperation. While for some, night trains hark back to an earlier time, these officials see them as a key element for the future as Europe strives to reduce its carbon emissions. "It is clear to me that night trains are the ecological alternative to short-haul flights and car journeys," said Austrian Transport Minister Leonore Gewessler. An Amsterdam-Cologne-Zurich service is also on track for December 2021 as well as a Zurich-Barcelona train in December 2024. Austria's OBB has been working for several years to bring back night train services, which withered away as cheap air travel boomed in Europe. The firm hopes to see the number of international night trains grow from 19 to 26 within four years, with passenger numbers climbing from 1.8 to 3 million per year. liu-fcz/rl/jj