The U.S. Federal Trade Commission will not try to block Google's acquisition of online ad-serving vendor DoubleClick, the agency said Thursday.

The commission voted 4-1 to approve the deal after an eight-month investigation. "After carefully reviewing the evidence, we have concluded that Google's proposed acquisition of DoubleClick is unlikely to substantially lessen competition," the majority wrote in a statement.

The commission downplayed concerns brought by some privacy groups. Privacy concerns are "not unique to Google and DoubleClick," and "extend to the entire online advertising marketplace," commissioners wrote.

Google, the provider of the most widely used search engine, announced in April that it planned to acquire ad serving giant DoubleClick in a US$3.1 billion deal.

That same month, three privacy groups, the Electronic Privacy Information Center (EPIC), the Center for Digital Democracy (CDD), and the U.S. Public Interest Research Group, filed a petition asking the FTC to block the deal unless Google made significant changes to its privacy policy. The groups argued that the combined company will have unparalleled access to Web users' personal information.

In late May, Google announced that the FTC was examining the deal for potential antitrust problems. The FTC can rule that a merger raises antitrust issues, and the agency can recommend remedies. If the merging companies don't reach a settlement with the FTC, the agency can see an injunction against the merger in a U.S. court.

FTC Commissioner Jon Leibowitz, in November, said the agency was reviewing the case on antitrust, but not privacy, grounds. The privacy groups have argued, however, that the privacy issue is related to antitrust partly because of the competitive edge Google would get in targeting advertising to specific people.

In December, EPIC and CDD filed a new complaint, asking FTC Chairwoman Deborah Platt Majoras to recuse herself from the case. Majoras' husband works for a law firm that is advising DoubleClick, but DoubleClick and the FTC said that the Jones Day law firm hasn't represented the company before the FTC.

(More to come.)

The IDG News Service is a Network World affiliate.