Vivendi launched legal action against Italian regulator Agcom over its ruling to prohibit the French group from holding large stakes in both Telecom Italia and broadcaster Mediaset.

According to a Financial Times source, Vivendi chairman Vincent Bollore followed up on threats to mount a legal challenge, after filing an appeal against the regulator last week.

Agcom said in April Vivendi must cut its stake in either Mediaset or Telecom Italia within a year, and gave it a deadline of 60 days to present a plan.

Vivendi holds a 28.8 per cent share of Mediaset, and is also the single largest shareholder in operator Telecom Italia with a stake of 24 per cent.

It recently tightened its grip on the Italian operator after successfully nominating ten executives to its 15 person board, while Vivendi CEO Arnaud de Puyfontaine was also appointed chairman of Telecom Italia earlier this month.

Vivendi made no secret of its desire to take control of the company, and received a boost after the European Commission cleared its plans on the condition Telecom Italia divested its stake in another media company, Persidera.

However, Agcom contests Vivendi’s position in Telecom Italia and Mediaset, because it goes against the country’s strict laws regarding ownership and control in the communication and media sectors.

Vivendi argued at the time of Agcom’s ruling it “neither controls nor exercises a dominant influence on Mediaset”.