A report in the Wall Street Journal said it wants firms that filed complaints against the search behemoth to allow the content to be made public.
That indicates that the EU is preparing formal antitrust charges against Google, sources told the WSJ.
The EU has spent five years so far investigating Google for alleged antitrust activities, infuriating American authorities who felt it has it in for US technology companies.
Google last year launched a charm offensive in Europe, in a bid to demonstrate that not everything it did was evil.
Google consistently denies that it acts as a bullying monopoly in the field of search – something that European publishers and others don’t necessarily agree about.