Maurice Levy, the Publicis chairman, this week appeared to have left the way clear for Sir Martin Sorrell's WPP to make a play for Grey after declaring that his company was unlikely to bid.
However, in an interview with the French newspaper Le Figaro, Levy qualified his lack of interest by saying it was not necessarily in the best interests of Publicis "to make a possible offer for the whole of Grey Group".
Observers suggest Levy may be pinning his hopes on Grey's eventual sale to an equity company, which might sell it off piecemeal.
It appears that the acquisition would not have played well with Procter & Gamble, led by its chairman, president and chief executive, AG Lafley.
Publicis-owned agencies handle 70 per cent of P&G's global business, the remaining 30 per cent being held by Grey. P&G warned recently of the dangers of "putting all your eggs in one basket where creative is concerned".
Levy said: "We must never forget that all we have done and produced at Publicis Groupe is entirely guided by the interests of our clients and of their brands and to better serve their performances."
Industry sources suggest that Publicis is mainly interested in MediaCom, Grey's highly profitable media buying division, which, unlike the main Grey network, is not so heavily dependent on P&G business.
Grey, which is valued at £805 million, was put up for sale by Ed Meyer, its 77-year-old chairman and controlling shareholder. Omnicom and Japan's Dentsu have indicated they are not in contention.
Levy insisted his decision not to bid was not because of problems in finding the cash but because buying Grey would not be in line with the group's strategic direction.
WPP is the most likely potential bidder. The company, which already owns J. Walter Thompson, Ogilvy & Mather, Young & Rubicam and Red Cell, has hired the investment bank Merrill Lynch to carry out due diligence on Publicis.
Live Issue, p12.