Vivendi chairman Vincent Bollore has upped his stake in the French media giant to 10.2% only days after an activist investor challenged his strategy for the company. Bollore acquired an extra 27.7 million shares for $687 million, and his stake is now double what it was only a few weeks ago.

Bollore is consolidating his grip on Vivendi in advance of an expected showdown next month with activist investor P Schoenfeld Asset Management, which has been calling for Vivendi’s board to sell Universal Music Group and also distribute $10 billion to shareholders in the form of a special dividend. Vivendi’s board, on the other hand, has proposed a buyback and dividend worth $6.2 billion to investors over the medium term.

Bollore and his board have resisted both calls, claiming that UMG remains a key part of Vivendi’s strategy and dismissing the inflated buyback as potentially damaging for the company’s long-term future.

Also up for discussion is a resolution from another minority investor, PhiTrust, that wants Vivendi to exclude itself from a new French law enabling long-term shareholders such as Bollore twice as many votes as newer shareholders.

Bollore seems to have funded the increase in Vivendi shares by selling off 22.5% of his Bollore Group’s stake in French advertising group Havas for $650 million, leaving his total stake at 60%.

Bollore has streamlined Vivendi ever since he first made public his intention to acquire a 5% stake in 2012. Since then Bollore has overseen the sales of Vivendi’s stakes in telcos SFR in France and Maroc Telecom in Morocco, as well as video game publisher Activision Blizzard. Vivendi’s share price has risen more than 30% since September 2012 as a result.

All eyes are now on what Bollore intends to spend the estimated $15 billion on to expand Vivendi assets UMG and Canal + in the coming months.