Citing a source familiar with the matter, the Wall Street Journal reported that the Google decision will be discussed by EU commissioners on Wednesday. That source claimed to the news outlet that European antitrust chief Margrethe Vestager made the decision to file charges after consulting with European Commission President Jean-Claude Juncker.
Google faces fines of as much as $6.6 billion if the charges are proven.
Google shares traded down about 1.6 percent on Tuesday, although most of those losses came in the morning. The stock was largely unchanged in after-hours trading.
Reuters had reported earlier that Google was likely to learn more on Wednesday about how Vestager will treat complaints about its market dominance.
However, industry and EU sources suggested to Reuters that Vestager (who took over as EU competition commissioner in November and has indicated she will not be rushed into concluding the five-year-old inquiry) was unlikely to announce charges against the U.S. Internet search giant.
A European Commission spokesman declined comment on Tuesday on whether Vestager, who is due to fly to the United States on Wednesday afternoon, would make a statement after the weekly meeting of all 28 EU commissioners in the morning.
That followed a comment on Monday by another commissioner, digital economy chief Guenther Oettinger, who said Vestager would make a statement on Google in days. Another EU official said he expected an announcement on Wednesday.
Asked about such remarks, Commission spokesman Margaritis Schinas told a routine news briefing on Tuesday: "The Commission does not always express itself on ongoing competition cases.
"If there is a time for announcements it will be announced, but there is nothing on this question today."
Google could not be reached by Reuters for comment.
Andreas Schwab, a member of the European Parliament who has pushed for the EU executive to consider even breaking up Google, told Reuters he expected the Commission to conclude its investigation and issue a statement of objections—effectively bringing charges against Google that could result in huge fines and orders to reshape its business in Europe.
—Reuters contributed to this report.