A cosy soirée a deux is poised to turn into an unruly bash, as muscleman Sir Martin Sorrell gatecrashes the genteel wooing of coquettish Aegis by dashing French Romeo Publicis .

The leisurely £1.57 billion ($2.76bn; €2.32bn) love-in between the world number four agency holding company and the London-headquartered media-buying and research group now looks set to become a no-holds-barred brawl as WPP Group enters the fray, seconded by US private-equity firm Hellman & Friedman.

However, it's anyone's guess as to which way the referee will jump. Especially as he is none other than Vincente Bolloré, French corporate raider and chairman of rival agency group Havas . On Tuesday Bolloré confirmed he had yet again upped his stake in Aegis, this time from 11.38% to 12.63%

Sideline observers predict that WPP and its henchman H&F will cherrypick the choicer parts of Aegis if they triumph in the contest, with the former snapping-up the victim's market research businesses and the latter gnawing off the media planning/buying elements for a future sell-on.

San Francisco-based H&F has track record in the ad industry, having bought a slice of Young & Rubicam back in 1996 and selling it to WPP in 1999.

All camps are zip-lipped about their battle plans.

Data sourced from Wall Street Journal Online; additional content by WARC staff