Italian website Lettera43 said Citigroup had approached former Prime Minister Silvio Berlusconi on behalf of Vivendi to offer to buy the family's 44% stake in Mediaset at more than 3.5 euros ($3.9) a share, well above Tuesday's closing price of 2.78 euros.

"Vivendi denies the L43 report," a spokesman said, adding speculation was only aimed at manipulating market prices. Citigroup declined to comment.

In a separate statement, the Berlusconi family's holding company Fininvest said it had never considered selling its stake in the country's top commercial broadcaster.

Fininvest said it continued to support Mediaset's plan to create a pan-European group by folding its Italian and Spanish businesses into a Dutch holding company.

Vivendi last week vowed to fight the corporate revamp in court after failing to block it at a shareholder meeting called for its approval.

With its 29% stake in Mediaset, which it built up after a failed pay-TV deal in 2016 locked the two groups into a legal battle, Vivendi could still create difficulties for the Italian firm.

The corporate overhaul is conditional on no more than 180 million euros being spent to mop up the shares of investors who head for the door - well below the value of Vivendi's stake.

Mediaset's share price on Tuesday fell below the price of 2.77 euros a share at which Vivendi can exercise its withdrawal rights.

Vivendi has not made clear whether it is prepared to sell its holding. Doing so would translate into a loss of around 320 million euros for the French group.

(Reporting by Elvira Pollina; Writing by Valentina Za; Editing by Jan Harvey)