Shares in Vivendi, in which billionaire businessman Vincent Bollore has a stake of around 20 percent, fell 2.5 percent at the start of trading. They later recovered some ground, but the stock remained down 0.9 percent by 0835 GMT.

Late on Thursday, Vivendi reported higher first-quarter sales and said it would review a possible change in the shareholding structure of its UMG music division, following two years of speculation about a potential listing.

"Group revenues of 3.11 billion euros (2.7 billion pounds) came in 1-2 percent below consensus mainly due to forex," said Exane BNP Paribas analysts, who kept a "neutral" rating on the stock.

"No timeline (on UMG IPO) was provided but we think this is a long process and an IPO is unlikely to materialise this year (if at all)," added Exane BNP Paribas.

For their part, Barclays analysts also wrote that some might be disappointed at the lack of a precise announcement of an initial public offering (IPO) for UMG.

"In our view, the market was expecting an IPO announcement, therefore only a proposal might disappoint," wrote Barclays.

Vivendi also resumed hostilities over Telecom Italia on Thursday with a threat to call a new shareholder meeting to change the Italian company's board, two weeks after it lost control to U.S. activist fund Elliott.

Brokerage Berenberg cut Telecom Italia's (TIM) target price, citing "a toxic cocktail", with Telecom Italia shares also falling on Friday.

Vivendi, which owns 24 percent of Telecom Italia, on Thursday said a "risk of a dismantling" of TIM could prompt the company to call another shareholder meeting to change the Italian phone group's board.

(Reporting by Dominique Vidalon and Sudip Kar-Gupta; Editing by Keith Weir)

By Dominique Vidalon and Sudip Kar-Gupta