Politicians and rival firms have long called on TIM to split off and upgrade the network, and pressure has risen since Rome objected to the growing influence of French media group Vivendi , TIM's biggest shareholder with a 24 percent stake.

Sources close to the matter told Reuters last month that regulator AGCOM was exploring whether it could force TIM to turn the network into a separate but wholly-owned legal entity.

AGCOM had planned to finish a market review before the end of this year, the sources said.

But regulatory commissioner Antonio Nicita said on Wednesday he expected to complete the analysis by the middle of next year.

There are three options open to the watchdog, Nicita said, including moving towards imposing a clearer functional separation of the network, which TIM values at up to 15 billion euros ($17.75 billion).

It could also decide to leave the system unchanged, Nicita said on the sidelines of an event in Rome, or loosen regulations in view of increased competition in the sector.

TIM's main rival in broadband is Open Fiber, a joint venture between utility Enel and state lender Cassa Depositi e Prestiti.

Italian market regulator Consob has ruled that Vivendi has de facto control of TIM, potentially opening the way to forced asset sales, which would be politically and commercially sensitive.

AGCOM is analysing "if new developments require different regulation", Nicita said.