The head of Porsche, Matthias Mueller, has had his contract renewed for another five years, the board of the German sports car company said on Friday. Mueller took charge of Porsche, a unit of Volkswagen, in October 2010 and his contract had been due to expire in January next year, before it was extended to the end of 2019. "Despite growth, we want to keep our Porsche culture, a path we are continuing with Matthias Mueller," the deputy chairman of the board, Uwe Hueck, said in the statement announcing Mueller's extension. Mueller was also kept on in his role as director of strategy and of development, the statement said.