PARIS, Jan 18 (Reuters) - Vivendi (VIV.PA) said it was investing in digital communication group Progressif Media through the purchase of a 8.5% stake from ZeWatchers, with the financial terms of this deal not disclosed. ZeWatchers will own a 30% in the company while the three Progressif Media founders, Emile Duport, David Bonhomme and Thomas Ghys, will retain 60% of the company.