* Vivendi, Altice Europe and Mediaset approached for M6 - sources * TF1 Group and billionaire Kretinsky also contacted - sources * Discussions at a preliminary stage - sources * Deal could value M6 at about 3 billion euros - sources (Adds detail on Mediaset, share price reaction) By Gwénaëlle Barzic, Arno Schuetze and Elvira Pollina PARIS, Jan 29 (Reuters) - Germany’s Bertelsmann has approached potential bidders including French media giant Vivendi and Altice Europe about selling its controlling stake in French broadcast group M6, sources close to the matter told Reuters. Bertelsmann is hoping for a deal potentially worth about 3 billion euros ($3.6 billion) for Metropole Television SA, commonly known as M6 Group and home to France’s biggest private radio station, RTL, two sources said on condition of anonymity. M6 shares jumped 9% in high volume on Friday after Reuters reported Bertelsmann’s sale plans. M6 Group’s flagship television channel M6 is France’s most profitable private national channel and part of the second-most-watched private TV network behind TF1, which is controlled by conglomerate Bouygues. M6’s French rival TF1 Group and Italy’s Mediaset have also been approached along with Czech billionaire Daniel Kretinsky, the sources said. Kretinsky owns stakes in French newspaper Le Monde and German broadcaster ProSiebenSat.1 and also controls French magazines including Elle. Bertelsmann has yet to hire banks for any formal sales process and talks remain at a preliminary stage, the sources said. Bertelsmann, M6, Vivendi, TF1, Mediaset and telecoms company Altice declined to comment. Representatives for Kretinsky were not immediately available to commen Founded in 1987 and led for the past twenty-one years by its charismatic boss Nicolas Tavernost, M6 is controlled by Bertelsmann via its subsidiary RTL Group. An RTL Group spokesman also declined to comment, but noted Bertelsmann CEO Thomas Rabe has repeatedly called for industry consolidation in Europe and the creation of national champions in the media sector. A full sale of RTL Group’s 48% stake in M6 would mark the departure of Bertelsmann from France after it agreed to sell Prisma Media, France’s number one print magazines group, to Vivendi in December. Bertelsmann has instead sought to strengthen its presence in the United States with the $2.175 billion purchase of publisher Simon & Schuster in November. In a Financial Times interview last year, Rabe mentioned the benefits of striking partnership deals and said RTL was “open-minded to exploring such possibilities.” He sees the creation of national TV champions in Europe’s fragmented media market as a way to better compete with U.S. streaming giants like Netflix. Broadcasters RTL and German competitor ProSiebenSat.1 Media are battling to recover from a hit to advertising revenues caused by the coronavirus pandemic.