Consob and Vivendi could not immediately be reached for comment.

U.S. hedge fund Elliott pulled off a boardroom coup at TIM last week, wresting control away from top investor Vivendi, following a two-month campaign to shake-up the way the French company has been running TIM.

Since becoming a shareholder in 2015, Vivendi had gradually tightened its grip on TIM, appointed the majority of its board last year and its own CEO as TIM's executive chairman.

Italy's government eventually used the so-called "golden power" last year to ensure it had a say in some strategic decisions at TIM, a move widely seen as a bid to rein in Vivendi's influence over the former state phone monopoly.

Vivendi has always denied controlling TIM.

On Friday, the regulator said Vivendi's stake in towers group INWIT, majority controlled by TIM, was reduced to zero from 60 percent after the May 4 shareholder meeting.

(Reporting by Stefano Rebaudo; editing by Luca Trogni)