MILAN (Reuters) – Telecom Italia (TIM) is looking to fetch a valuation of at least 25 billion euros ($26 billion) including debt for its grid under a plan to separate its fixed-line assets from its services arm, two sources close to the matter said. The price tag is closer to the 31 billion euro figure sought by TIM’s top shareholder Vivendi in any potential network deal than initial estimates provided by two sources in line with analysts estimates. In May sources had told Reuters TIM has started looking at a valuation of around 20 billion euros, including debt and before any synergies, in a p…