Italy's competition authority has opened a formal investigation into the 5G network agreement between Fastweb and Telecom Italia (TIM), Reuters reports. The probe puts one of the Italian market's most significant next-generation infrastructure arrangements under regulatory review at a delicate moment for both operators.

The deal under scrutiny concerns cooperation between the two carriers on 5G network infrastructure. Fastweb, the Swisscom-owned Italian operator, and TIM, the country's largest telco, had struck an arrangement intended to extend 5G coverage — an arrangement that has now attracted the attention of the Italian Competition and Market Authority, known as AGCM.

For AGCM, the question is whether the agreement between two major players in the Italian mobile market risks restricting competition. Network sharing deals are common across Europe as operators look to cut the cost of rolling out 5G, but regulators have grown more willing to examine them closely where the parties involved hold significant market power between them. Italy's mobile market remains one of the most competitive and price-pressured in Europe, and any arrangement that concentrates network control in fewer hands draws scrutiny.

TIM has been pursuing infrastructure-sharing agreements as part of a broader effort to reduce its cost base. The operator carries a heavy debt load and has faced years of shrinking revenues in its domestic market. For Fastweb, a fixed-line challenger that moved into mobile, network cooperation with an incumbent offered a faster and cheaper route to national 5G coverage than building radio infrastructure alone.

The opening of an antitrust probe does not imply wrongdoing. It marks the start of an examination in which the regulator will assess whether the arrangement conforms to Italian competition law, and the companies will have the opportunity to present their case. The investigation nonetheless adds a layer of uncertainty over the timetable of the cooperation, since regulators can attach conditions or, in the most serious cases, require modifications to an agreement before allowing it to proceed.

The case also lands against a backdrop of intense regulatory attention to the structure of Italy's telecom sector. TIM's network business has been the subject of a long-running and politically sensitive takeover effort by state investor CDP alongside Open Fiber, aimed at creating a single national network operator. Any probe touching TIM's network arrangements will be read in that wider context, even though the Fastweb investigation is a separate proceeding focused specifically on competition questions around the 5G deal.

Neither Fastweb nor Telecom Italia has commented publicly beyond acknowledging the regulatory process, according to the Reuters report. Both companies now face a waiting period while AGCM gathers evidence and determines whether the arrangement raises competition concerns serious enough to require action.

The outcome will matter beyond the two companies involved. If AGCM clears the deal, Fastweb and TIM can press ahead with a shared 5G build that spreads infrastructure costs across two balance sheets. If the regulator intervenes, other European operators watching the Italian case may need to reconsider how they structure their own network-sharing agreements.