The latest stake increase takes the Havas chairman's holding in Aegis up from 20.13%, where it stood at the end of last week. Bollore is expected this week to make his intentions clearer, having moved beyond the 20% threshold.
The speculation is that he could now demand representation on the board of Aegis. If Bollore acquires shares giving him 30% or more of voting rights in Aegis, he is bound to make a bid for the company under UK regulations.
The latest move by Bollore follows the news on Friday that Aegis had appointed Mainardo de Nardis, the CEO of WPP Group's Mediaedge:cia, to the global role of CEO of Aegis Media.
De Nardis leaves Mediaedge:cia, and its forerunner CIA-MediaNetwork, after more than 12 years to join Aegis.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the