The new body will be called the Communications Agency Federation, and the founding members are the IPA, the Public Relations Consultants Association and the Marketing Communication Consultants Association.
The formation of the CAF comes after a report by consultant Mark Boleat. He had been asked by the three bodies in September to review the structure and assess the merits of pooling resources.
The IPA, MCCA and PRCA have since been looking at the possibility of merging to form a "big tent", giving the whole communications industry a stronger voice.
In Boleat's report, he concludes that the present structure is broadly right and appropriate for the industry and that there was no strong case for the associations to merge.
"Communications agencies have been well served by their trade associations, each of which enjoys strong member support," Boleat said. "The associations increasingly work together on matters of common interest. While there is no strong case for the associations seeking to merge, they do need to strengthen their relationships in order to best serve their increasingly overlapping memberships."
A federation, according to Boleat, would be the most effective and low-cost way of achieving stronger relationships.
The council for the new federation will comprise the presidents and chief executives of the three founding members, and will meet at least quarterly. It will have a rotating chairman and one of the chief executives will act as secretary. There are no plans for it to have its own staff, offices or funds.
The federation will be open to other communications associations joining, including the Direct Marketing Association.
Ealier this year, the DMA rejected proposals to share offices and merge its agency section to create a single trade body, instead favouring to simply work jointly with the IPA when the need arises.
At the time James Kelly, managing director of the DMA, said: "The IPA did sound out various trade bodies and we did meet with them to discuss a range of issues. These were sharing a building, forming a new body to look after agencies and looking at ways to do things jointly."
CAF will be established with immediate effect. One of the first issues it should look at, according to Boleat, is the growing threat to freedom to advertise and representation in Europe.
Bruce Haines, president of the IPA, said: "We have accepted this conclusion and have established the federation to formalise and develop our working relationship."
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