Users from the northern city of Milan to the Sicilian capital Palermo reported problems, with the issue mainly focused on fixed-line internet services.
Some soccer fans bemoaned interruptions to their streaming of the Serie A game between Spezia and league leaders Napoli.
"An international interconnection problem impacting the service at national level was detected. Analyses are underway to resolve the problem," a TIM spokesperson said.
There was no indication that the problems were caused by hackers, Italy's ANSA news agency reported.
TIM, the former national telecoms monopoly, is at the centre of a takeover struggle, with private equity group KKR having made a non-binding bid to buy its network.
(Reporting by Keith Weir and Elvira Pollina; Writing by Keith Weir; Editing by Jan Harvey)
https://www.msn.com/en-us/money/companies/italys-tim-suffers-internet-connection-problems/ar-AA177WgR