Some of the biggest agency groups in the world are withholding financial results for their public relations brands in case they violate US accountancy rules.

WPP Group, Omnicom Group, Interpublic Group, Grey Global, Publicis Groupe and the Euro RSCG unit of Havas have decided after legal advice that new financial disclosure rules from the Securities & Exchange Commission prevent them from releasing details of their PR networks to compilers of agency league tables.

Under SEC regulations adopted in January, the groups cannot make disclosures that do not conform to the Generally Accepted Accounting Principles specification laid down by the SEC.

Their refusal to hand over information hits tables such as PRWeek’s list of the top 150 UK agencies.

Commented Omnicom’s European ceo Anthony Wreford: “We recognise there's a meeting of interests between us and league table publishers, and that the rankings are a measurement device for agencies, but we face forces beyond our control.”

Whether the rules prevent the compilation of non-PR agency tables has not been determined.

Data sourced from: BrandRepublic (UK); additional content by WARC staff