PARIS, Nov. 13 — European Commission competition authorities refused today to approve Google’s $3.1 billion purchase of DoubleClick, the Internet advertising company, and ordered an in-depth review amid opposition from rivals, publishers and consumer groups.

The commission, which rules on antitrust issues for the 27 countries in the European Union, said the merger raised competition concerns and required a more thorough review of its impact on the Internet advertising business.

The inquiry is one of very few major business challenges that Google, the world’s dominant Internet search engine and a star stock market performer, has encountered in its nine-year history. The company makes the bulk of its money by selling ad space next to search results, while DoubleClick, a privately held company, places banner ads on Web sites and sells analysis of who sees them.

“We are obviously disappointed,” Eric E. Schmidt, chief executive of Google, said in a statement. Saying the company would work with the commission, he added, “We seek to avoid further delays that might put us at a disadvantage in competing fully against Microsoft, Yahoo, AOL and others whose acquisitions in the highly competitive online advertising market have already been approved.”