MILAN, March 14 (Reuters) - KKR is pressing ahead with preparatory activities for the buyout of Telecom Italia's (TIM) fixed line network and working with other parties towards the summer 2024 timeframe for finalising the deal, a spokesperson for the U.S. fund said on Thursday.

Backed by the Italian government and worth up to 22 billion euros ($24 billion), the deal is opposed by TIM's top investor Vivendi, which has questioned the sustainability of the remaining business and is fighting the sale in court.

($1 = 0.9186 euros) (Reporting by Elvira Pollina Editing by Keith Weir)