Vivendi has asked for the lawsuit to be put on ice pending a ruling by a European Union court on a related case.

Mediaset, controlled by the family of former Prime Minister Silvio Berlusconi, is seeking 3 billion euros (2.6 billion pounds) in damages from Vivendi after it backed out of a deal to buy Mediaset's pay-TV unit Premium in July 2016.

After pulling the plug on the deal, Vivendi, which has said it fell through when the French company realised the agreement differed from original discussions, built up a 28.8 percent stake in the Italian broadcaster - a stake which Mediaset considers illegitimate.

Vivendi has since been forced by Italy's media regulator to transfer a stake of around 19.2 percent to a trust. The French company has challenged the regulator's decision and is awaiting a ruling on the matter by the Court of Justice of the EU.

"The French group asked for a suspension... A decision will come after April 30," the legal source said following a closed-door court hearing in Milan.

(Reporting by Elvira Pollina; editing by Jason Neely)