The findings led to JP Morgan temporarily stopping its $250m adspend to launch an investigation into the relationship with its agencies, according to The Wall Street Journal. It is understood this suspension recently ended.
It also reports that General Electric, Sears Holdings and Nationwide Mutual Insurance are auditing their media businesses as well.
In response, Publicis Groupe said audits are part of the normal course of business and was being collaborative.
The ANA report was revealed in June and found "numerous non-transparent" practices at media agencies in the US.