COLOGNE, Germany — Germany’s struggling Vox television station will go off the air by the end of the month unless its biggest shareholder, Bertelsmann AG, finds new partners, company officials said Tuesday.Manfred Lahnstein, Bertelsmann director of electronic media, told a news conference the German media group and its partners in Vox had decided to cancel their contractual relationship effective March 31. Between now and then Bertelsmann’s film unit Ufa Film-und Fernseh GmbH would pump new funds into Vox to keep the lights on, hoping to strike a deal with potential investors. “It must be successful by the end of March with a new partner,” Lahnstein said. “Without a partner there will be no second chance.” Lahnstein said Ufa was negotiating on behalf of Vox with three to four investors, including Canada’s biggest private television company, CanWest Global Communictions Corp. He would not name any other partners in the negotiations. According to German press reports, Westdeutsche Allgemeine Zeitung and Luxembourg media group Compagnie Luxembourgoise de Telediffusion are interested in Vox. Both CLT and WAZ are partners with Bertelsmann in the successful German RTL Plus TV station. Vox went on the air in January 1993 with a program mix of infotainment and feature films aimed at a young, educated audience. But it never fared well in viewer ratings, and advertisers failed to show up in numbers high enough to offset mounting startup losses. Lahnstein said the station has racked up losses totaling 390 million marks ($ 227 million) since 1992. After the announcement at a tense shareholders’ meeting last month, all partners except for Bertelsmann decided to bail out, forcing Bertelsmann to decide by Tuesday to either join in and cancel its obligations or be contractually bound to take responsibility for 100% of Vox’s liabilities. Bertelsmann holds a stake of 24.9% directly and another 14.5% through a trustee. Other shareholders include Westdeutsche Landesbank Girozentrale, film producer DCTP and publisher Georg von Holzbrinck. Bernd Schiphorst, Ufa chairman and director of Vox, said it needed to boost its ratings to around 6% from less than 2% to be profitable.