The French financier has increased his stake in the media buying and research firm several times in the recent days.
Last week, he increased it to 9%, making him the biggest shareholder in the group. The latest increase allows him to block any delisting of the media group from the Stock Exchange should French rival Publicis go ahead with its bid.
Le Figaro has reported that Bollore may be ready to sell his stake in Aegis to Publicis. Bollore has said he views the Aegis investment as a short-term one and he said again on Friday that there was no question of combining Aegis and Havas. "They are two totally separate investments," Bollore said.
However, increasing his stake again will lead analysts to question exactly what his motives are. It could simply be a bargaining chip allowing him to win something from any Publicis and Aegis merger.
Bollore could now demand that Publicis sell part of Aegis off to Havas. It could potentially pick up Vizeum, the smaller of Aegis's two media networks.
Like Publicis chairman Maurice Levy, Bollore has held talks with Aegis CEO Robert Lerwill, but the talks have so far come to nothing. Havas was seen as a potential buyer for Aegis before Publicis entered the race.
A merger of Havas and Aegis would bring together media planning and buying networks Carat and Vizeum with the French group's Media Planning Group.
It is also been speculated that if Publicis does buy Aegis it will sell off its market research arm, Synovate, with WPP Group seen as one potential buyer. Synovate is believed to be worth around £320m and will likely attract interest from all Europe's market research groups, including France's Ipsos and the UK's Taylor Nelson Sofres.
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