Angela Merkel, who is the favorite to become German chancellor after elections on September 18, assured Russian President Vladimir Putin on Thursday that strong German-Russian relations would survive any change in government. Putin met Merkel, the conservative opposition leader, straight after joining Chancellor Gerhard Schröder to oversee the signing of a deal to build a five-billion-dollar pipeline linking Germany and Russia which underlined the strength of relations between the World War II foes. Merkel, whose conservative opposition alliance has a clear lead over Schröder's Social Democrats in opinion polls, said she insisted that Germany's ties with Russia must endure. "It is good when the relations are supported by good personal relations but they must exist without good personal relations too," Schröder said. Putin dismissed suggestions the decision to bring forward the pipeline-signing deal -- it had due to take place in October -- had been intended to help Schröder's re-election campaign. Merkel grew up in communist East Germany and speaks Russian, but her Christian Democratic Union party is more critical of Russia than Schröder has been. It has accused the chancellor of putting economic cooperation ahead of human rights concerns -- and trouble could be brewing over the pipeline too.