Vivendi has been a hostile Mediaset shareholder since the tycoons who control them, Vincent Bollore and former Italian prime minister Silvio Berlusconi, fell out in 2016 over an aborted pay-TV deal. They have been in a legal war ever since.

Mediaset, which considers Vivendi's stake as illegitimate and bars it from voting, plans to put the Italian broadcaster and its separately-listed Spanish unit under a new Dutch holding company as part of a pan-European growth strategy.

Publicly declaring its voting intentions for the first time since the June announcement, Vivendi said on Monday that it had petitioned a Milan court to issue an order allowing it to attend and vote at Mediaset's special shareholders meeting on Sept. 4.

Two-thirds of Vivendi's 29% stake in Mediaset is held by an arms-length trust which is barred from voting by an Italian court. That leaves Vivendi with 9.99% direct voting rights, not enough to block the deal on its own if it were allowed to vote.

At the Sept. 4 meeting, shareholders will be asked to approve the creation of a new entity, Media for Europe (MFE), which will carry out a reverse takeover of Mediaset and Mediaset Espana.

No date for a court decision on Vivendi's petition has been set yet, according to a source close to the matter.

"During the meeting, Vivendi intends to vote against the proposed merger of Mediaset into Media for Europe NV (MFE). This is because the group has assessed the rights, or lack of them, that minority shareholders and particularly Vivendi would have under the proposed MFE bylaws," Vivendi said in a statement.

A Mediaset spokesman declined to comment.

Vivendi built its stake in Mediaset after it reneged on an agreement to buy Mediaset's pay-TV business. Later, Italian regulators forced Vivendi to transfer most of its voting rights into a trust because of antitrust concerns, as Vivendi is also a top shareholder in Telecom Italia.

Vivendi wants to vote against Mediaset's plan because a bylaw of the new MFE holding company would exclude it from voting at shareholder meetings of the new entity..

Under the proposal, Fininvest, the Berlusconi family holding company, would own around 35% of MFE and hold just above 50% of the voting rights.

Mediaset shares were 0.2 percent higher in a firmer overall market after Vivendi's statement. Mediaset Espana stock fell 1 percent while Vivendi shares edged down 0.2%.

(Editing by Kirsten Donovan and Mark Bendeich)

By Sudip Kar-Gupta and Elvira Pollina