German Economics Minister Karl-Theodor zu Guttenberg departed today for the United States, where he is to hold talks with the US government and General Motors (GM) on the future of German subsidiary Opel, dpa reported. During the first transatlantic trip since he took up the post, Guttenberg faces tough negotiations over Opel's ownership structure. On the eve of the 80th anniversary of GM's partnership with the German car manufacturer, Germany is looking for ways of separating the two, to prevent possible government funds aimed at propping up Opel from flowing into US coffers. On Tuesday, he is scheduled for talks with the new US Finance Minister Timothy Geithner and Larry Summers, economics advisor to US President Barack Obama. GM's survival depends in part on US government funding, making Guttenberg's appointments in New York and Washington crucial to thousands of car assembly workers in Germany and across Europe.