The U.S. Federal Trade Commission has sought information from some of the world's top advertising firms as part of a probe into whether advertising and advocacy groups violated anti-trust laws by coordinating boycotts of certain sites, the Wall Street Journal reported on Monday.
Omnicom (OMC.N), WPP (WPP.L), Dentsu (4324.T), Interpublic Group (IPG.N) and Publicis Groupe (PUBP.PA), Havas and Horizon Media are among the agencies that the FTC sent letters to on Monday, the report said.
Reuters could not immediately verify the report.
The recent civil investigative demands are part of the FTC's probe of organizations including nonprofit U.S. media watchdog Media Matters and Ad Fontes Media, which rates the quality of news sources for advertisers, the WSJ report added.
U.S. media watchdog group Media Matters sued Elon Musk's X in March, accusing it of bringing "abusive," costly and meritless lawsuits to punish Media Matters for its reporting on advertising on X after Musk bought the social media platform.
In May, the FTC demanded documents from Media Matters about possible coordination with other media watchdogs accused by Musk of helping orchestrate advertiser boycotts of X.
FTC, Omnicom Group, WPP, Dentsu, Interpublic Group, Havas and Publicis Groupe did not immediately respond to Reuters' requests for comment, while Horizon media declined to comment on the report.
