Instead, it has suggested the establishment of an informal federation that would allow them to exchange views, co-ordinate their work more closely and run joint projects.
The recommendation will lead to the immediate establishment of what is to be called the Communications Federation, which will include the IPA, the Marketing Communication Consultants Association and the Public Relations Consultants Association.
The idea of a "supergroup" was first floated by Hamish Pringle, the IPA's director-general, a year ago, as a way of giving the industry greater clout with the Government and the European Union at a time of growing legislative and regulatory threats.
But the report by Mark Boleat, the former director- general of the Association of British Insurers, says there is no case for mergers although there was merit in the trade bodies pooling resources.
Boleat said: "While there is no strong case for the associations seeking to merge, they do need to strengthen their relationships. An informal federation is the best means of achieving this in the short term."
The report says an informal federation would allow the trade bodies to share information and make joint representations at minimal cost. It suggests the move could extend to the bodies sharing accommodation although this was probably not practicable in the near future.