Publicis revealed at a press conference on Tuesday that it planned to swap staff with Google as part of a partnership aimed at benefiting clients by pooling their respective creative and technical know-how. The companies' top executives said that they had been working together for the past year.
Levy, the Publicis CEO, said: "Google is not a short-term friend and a long-term enemy", in a comment clearly directed at Sorrell, who categorised Google in exactly those terms last year.
In Davos, Sorrell, the WPP Group chief executive, was dubious that there was much substance in the partnership between Publicis and Google, which he has also described as a "frenemy".
He told Reuters: "Next time I meet with [Google CEO] Eric Schmidt, I think we'll send out a press release. This morning I met with Maurice Levy, does this mean we're putting together a joint venture?
"What Publicis is doing represents a little bit of a concern that they didn't get the technology right. I think Maurice is acknowledging a bit of an Achilles heel when it comes to technology."
Levy hit back at his rival: "I'm sorry Martin said that -- it's really cheap, but it's probably the result of his lack of understanding of technology.
"He's a financier, I'm an engineer, and you can see the difference. I'm pleased with what we have done, and I'm sorry that my dear friend has not understood it."
Speaking earlier this week on the 'Today Programme' on BBC Radio 4 in the wake of the .75% US Federal Reserve rate cut, Sorrell said that he sees 2008 as being another good year for the advertising industry and that it is 2009 that is of concern.