By Syndicated Content By Christoph Steitz and Jan Schwartz FRANKFURT (Reuters) â The Porsche and Piech families, who control Volkswagenâs largest shareholder, are prepared to take a direct stake in Porsche AG should the luxury carmaker be separately listed, two people familiar with the matter said. Such a move would loosen the familiesâ grip on Europeâs largest carmaker Volkswagen, in favour of direct ownership of the iconic sports car brand, founded by their ancestor Ferdinand Porsche, which dates back to 1931. Speculation about a listing of the unit earlier this year included estimates of a standalone valuation of Porsche AG ranging from 45 billion to 90 billion euros ($55 billion-$110 billion), compared with 135 billion for the Volkswagen group.