(Telecompaper) French billionaire Xavier Niel, founder of internet provider Iliad, has acquired the equivalent of an 11.2 percent voting stake in Telecom Italia, according to a filing with Italian markets regulator Consob. The development comes just a few days after French media conglomerate Vivendi, led by fellow billionaire Vincent Bollore, boosted its stake in Telecom Italia to just over 20 percent of the company's ordinary shares. Niel acquired a stake of around 6 percent via a personal investment company and an additional 5 percent through derivatives, according to unnamed sources cited by Bloomberg. Iliad is the parent company of French mobile operator Free, which has transformed the local telecoms sector since launching in 2012 with a low-tariff policy that has led to a 40 percent fall in prices. Niel has also invested in mobile operations in Switzerland (Orange) and Monaco (Monaco Telecom) in recent years.