Groupe Arnault, the investment vehicle of Bernard Arnault, the impresario behind luxury goods maker LVMH Moet Hennessy Louis Vuitton, has increased its stake in fashion house Christian Dior SA. According to a statement from financial services regulator Conseil des Marches Financiers, the Arnault-run company has increased its holding in Dior from less than two thirds to 67.15 per cent.