Embattled Vivendi Universal boss Jean-Marie Messier risks upsetting another powerful shareholder – US cable pioneer John Malone.

In December, Malone’s Liberty Media investment vehicle agreed to sell to Vivendi its 20% stake in USA Networks and 27% holding in European TV channels company Multithematiques, in return for 3.6% of Vivendi.

The deal is due to close in the middle of this month. However, since the original agreement Vivendi shares have fallen so far as to wipe out almost half the 3.6% stake’s value. In December, the French media group’s shares stood at €52.10 ($47.67; £32.50), valuing the holding at around $1.9 billion; last week they traded at €31.52.

Messier is under pressure from disgruntled shareholders to resign. Malone – who will become one of Vivendi’s biggest shareholders when the deal is completed – is not expected to call for his replacement immediately, and is believed to have waived the right to renegotiate the deal.

However, one Liberty insider warned: “We will not be patient forever. We think they have a strategy on the media side. But we would like them to keep their heads down and execute.”

Data sourced from: Financial Times; additional content by WARC staff