After years of back and forth, European authorities appear poised to take action against Google over how it conducts its search business.

According to The Wall Street Journal, the European Commission has asked those who filed confidential complaints against Google for permission to make some of those filings public.

The move, according to the paper, signals that the EU could be ready to file formal antitrust charges.

The battle between Google and the EU dates back to 2010, when the European Commission opened an antitrust investigation into Google over allegations that the company abused its dominant position in online search.

Last year, the EU announced a deal whereby Google would feature links to rival services in its results, as well as make it easier for advertisers and publishers to work with competing firms. But former competition chief Joaquín Almunia re-opened the case in September, after a number of Google rivals pushed back and requested further concessions.

The bureau is now in the hands of Margrethe Vestager, who said in November that she would take her time to investigate unease over Google's search-related business practices.

As the Journal noted, Google could still broker a deal even if antitrust charges are filed. But it's a major case, similar to EU's long-running probe of Microsoft, which resulted in more than $1 billion in fines.

The EU is also separately probing Google's Android operating system, but as of last year, had made no decisions whether to open a formal investigation.

In the U.S., the Federal Trade Commission (FTC) in 2013 found that Google did not unfairly manipulate its search results to highlight its own products and demote competing firms. There was some debate over that investigation just last month, as documents related to the case were leaked, but the FTC denied any wrongdoing.