French corporate raider Vincent Bolloré plans to up his recently increased 10.4% stake in global agency group Havas, hiking this to around 15%.

Denying that he has any "current" intention of seizing control of the world's sixth largest marketing services group (by global billings), Bolloré's move piles further pressure on chairman/ceo Alain de Pouzilhac to accede to his demands for a boardroom shakeup.

Whatever his motives, Bolloré has chosen the moment of optimum vulnerability to press home his demand that Havas revamp its board. The Paris-headquartered group launched a $490 million (€399.64m; £273.0m) rights offering on 17 September. The investor's agreement to this is essential if the deal has any chance of succeeding

In an attempt to mollify the savvy raider, de Pouzilhac is is mulling the division of Havas' board into two separate segments: management and supervisory. This would allow Bolloré representation among the company's directors and prevent him mounting a takeover bid.

Observers believe Bolloré may be handed the two board seats he has demanded, a burnt offering de Pouzilhac hopes will placate the investor and anchor the group's stability during the rights issue.

Data sourced from AdWeek (USA) and Financial Times; additional content by WARC staff