Wednesday's ruling by Braunschweig state court in northern Germany appears to strengthen Porsche's position, which still faces other court battles in connection with the 2008 takeover bid, German news agency dapd reported.
Two investors in the Braunschweig case had sought $6.1 million in damages claiming that Porsche published misleading information while it was secretly trying to take control of the much-larger Volkswagen.
Porsche's bid failed amid an unsustainable debt burden and the collapse of financial markets following the Lehman Brothers bankruptcy, eventually leading Volkswagen to take full control of Porsche.