Most Telecom Italia investors sign up to vote on board's future MILAN (Reuters) - Investors with a combined 53.8 percent stake in Telecom Italia have registered so far for a key shareholder meeting on December 20 that will decide whether to oust the board, the company said on Tuesday. It means Telecom Italia's controlling investor Telco - which has a 22.4 percent stake - will need the backing of other investors to fend off a proposal by rebel shareholders to remove the board. To pass, the proposal needs a majority of 50 percent plus one vote of shareholders at the meeting. In a statement, Telecom Italia said the shares registered include a stake of over 4.8 percent held by U.S. giant investor BlackRock and its affiliates. More shareholders can register between now and the meeting, which was called by Italian businessman Marco Fossati, a rebel investor with a 5 percent stake in Telecom Italia. Telecom Italia is controlled by Telco, a holding company grouping Telefonica, Italian banks Intesa Sanpaolo and Mediobanca, and insurer Generali. The vote could be crucial for the future strategy of Telecom Italia, and especially for its position in Brazil, where it is a direct competitor to Telefonica. Fossati believes the influence of Telefonica could lead Telecom Italia to sell its prized Brazilian unit TIM Participacoes, reducing growth options for the Italian group. Reporting by Danilo Masoni; editing by Tom Pfeiffer