If not Publicis, Aegis is likely to end up in another rival's clutches. And, if a bidding war does erupt, then the key question will be: "Who needs Aegis most?"
Undoubtedly, the strength of Carat in Europe would be a massive benefit to Publicis' European offer, which lags someway behind its US strength. Equally, there is clear sense in Omnicom moving for Aegis - though it usually likes to grow its businesses organically, Aegis would give Omnicom another strong global media network to complement OMD, something that PHD hasn't been able to offer.
Havas' Vincent Bollore has a small stake in Aegis, but question-marks surround his willingness to pay a premium for the company. WPP has yet to show signs of interest, but tends to have a look at everything available. The only sure thing is that IPG won't be bidding.