By Danilo Masoni and Stefano Bernabei MILAN/ROME (Reuters) – An activist shareholder campaign to reform Telecom Italia won traction on Wednesday as influential proxy adviser ISS recommended institutional investors back a proposal to remove the company board at a meeting on December 20. The potentially disruptive vote comes as Italys biggest phone company by market share tries to revive years of sluggish growth and share underperformance while at the same time cutting its 28 billion euros of debt. Businessman Marco Fossati, Telecom Italias No.2 investor through his 5 percent stake, and small shareholders group ASATI have proposed to oust the Italian phone companys board, which they say caters more to the interests of core shareholders such as Spains Telefonica than to other investors. Holding company Telco, which owns 22.4 percent of Telecom Italia, is controlled by Telefonica together with Italian financial companies Assicurazioni Generali, Intesa Sanpaolo and Mediobanca.