Last October, CNIL and its counterparts in Britain, the Netherlands, Germany, Spain and Italy gave Google four months to bring its practices into line with the relevant European Union directives.
The regulators asked Google to provide search-engine users with clear, complete information about the nature of the personal data collected, how long the data is retained and for what purposes.
As Google failed to make any changes following a March 19 meeting between company executives and the regulators, the six national agencies will undertake legal action in accord with the respective laws in each country, CNIL said Tuesday.
While even successful court cases would lead only to comparatively modest fines, the controversy may harm Google's standing with the public and constrict its ability to collect data.
Google moved last year to consolidate 60 separate privacy policies is use around the world into a single, universal procedure, citing the need for simplicity.
CNIL and like-minded European regulators fault the new policy for a lack of transparency and for failing to give users control over the use of their data.