The French conglomerate is planning to offer shareholders stock in UMG, which would then be listed in Amsterdam by the end of September. Activists including Bluebell Capital Partners and Artisan Partners have been lobbying against the plan, saying it will lumber most shareholders with a heavy tax bill and needs to be organized differently.

Shareholders voted 99.88% to spin off UMG, home of Taylor Swift, Drake and Billie Eilish, and also backed plans for a share buyback of as much as 50%, at Vivendi’s annual general meeting on Tuesday.

The acceptance of both the plan to spin off UMG and potentially start a significant buyback is a victory for French billionaire Vincent Bollore, the company’s controlling shareholder.

Bluebell has argued that the buyback could allow Bollore to tighten his grip on Vivendi. Proxy advisers Glass Lewis and ISS also recommended shareholders oppose the move, saying Vivendi hasn’t properly explained its intentions.

“The company has not provided any compelling arguments to support the buyback program,” ISS said in its voting recommendations.

Bollore’s holding company has denied any plans for a power grab but has also asked France’s market regulator not to exempt it from making a public takeover bid if it crosses the 30% threshold, the usual practice under the country’s law. Bollore’s firm currently controls about 30% of Vivendi, according to data compiled by Bloomberg.

The billionaire may be waiting for a fall in Vivendi’s stock price that would allow him to buy out other shareholders at a cut price, said Denis Branche, managing director of Phitrust, a French investor that lobbies on corporate governance issues.

UMG was valued at 35 billion euros ($41.6 billion), including debt, in its deal to sell a 10% stake to U.S. investor Bill Ackman’s blank-check vehicle Pershing Square Tontine Holdings Ltd. On Sunday, Ackman agreed to acquire the holding for about $4 billion. Vivendi has a market value of about 33 billion euros.