France's industry policy, dubbed nationalistic by Germany, is putting pressure on the close alliance between the countries just days after their regular expressions of warmth culminated in joint D-Day commemorations.
Germany hopes French Finance Minister Nicolas Sarkozy is alone with what Berlin officials see as a France-first approach they believe is motivated by his ambitions to succeed Jacques Chirac as president in 2007.
Sarkozy's blunt refusal in recent weeks to let Germany's Siemens take over parts of troubled French engineering giant Alstom to form a European champion infuriated the Berlin government.
And in another knot in relations, German Economy Minister Wolfgang Clement effectively rebuked Sarkozy for demanding this week that the European Central Bank do more to boost growth.
"We shouldn't seek to influence the ECB like this, we have to give regard to and respect its independence," Clement told reporters.
German officials kept their cool after France backed a take-over of Franco-German drugs group Aventis by French rival Sanofi-Synthelabo earlier this year, in the hope that the next big deal would be under German control.
But the calm has gone and the Germans now see Sarkozy as the villain. Chancellor Gerhard Schroeder was reported by a newspaper to have called him "extremely nationalistic", while Clement denounced French "interventionism".
"You cannot blame that on Chirac, it's Sarkozy," said one German official who, like all functionaries in Berlin, refused to be identified on this sensitive issue. "Sarkozy wants to position himself against Chirac and is playing the national card without any restraint."