A Memorandum of Understanding (MoU) with UTILITALIA, a federation of 500 of the country’s electricity, gas and water companies, enables TIM to use their pipes, ducts and public lighting networks.
The Italy-based operator will have to sign separate agreements with individual companies, however.
In a statement, TIM said the MoU would reduce the costs of digging fibre as well as reduce disruption to locals and traffic.
TIM’s fibre network currently reaches 71 percent of the country, including more than 17 million homes in around 2,100 municipalities.
The operator had over 1.5 million FTTH and FTTC customers at the end of June, up 723,000 year-on-year.
It is investing €5 billion in its fixed and mobile broadband network 2017 and 2019 as it aims to reach 85 percent fibre coverage by the end of 2017 and 99 percent by the end of 2019.
In the first six months of 2017, TIM saw capex jump by €51 million to €1.63 billion versus the corresponding period last year.
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The deal with UTILITALIA follows a similar one TIM signed with regional utility A2A to roll out fibre in Milan in April.
Earlier this week, Vodafone announced plans to spend around €2 billion on rolling out FTTH and upgrading its cable network.