Last year AGCOM asked Vivendi, which owns 24 percent of TIM and just under 30 percent of Mediaset, to reduce its stake in one of the two groups by April this year to comply with Italian antitrust regulations designed to prevent a concentration of power in the country's telecoms and media sector.

Vivendi last month transferred a 19.19 percent shareholding in Mediaset into a trust. On Friday, activist fund Elliott wrestled board control at TIM away from Vivendi, raising the question over whether this would impact the regulator's view on the French media group's holdings in the two companies.

"The governance change (at TIM) does not alter the situation which AGCOM examined at the time," AGCOM commissioner Antonio Nicita told Reuters.

(Reporting by Alberto Sisto, writing by Agnieszka Flak)