The Federal Trade Commission (FTC) announced Thursday that Googles controversial $3.1 billion merger proposal with DoubleClick can proceed, despite earlier complaints raised by competitors and privacy advocates.

FTC regulators had been reviewing the proposed merger for eight months for possible antitrust violations, after Google announced plans in April to acquire the online ad-serving company. The commission, in issuing its decision to let the merger move forward, said the companies are not direct competitors in any relevant market.

"The markets within the online advertising space continue to quickly evolve, and predicting their future course is not a simple task. Because the evidence did not support the theories of potential competitive harm, there was no basis on which to seek to impose conditions on this merger,س according to an FTC statement.

The approval for the merger came in a 4-1 vote by regulators. In her dissent, Commissioner Pamela Jones Harbour said she was inclined to make زalternate predictions about where this market is heading, and the transformative role the combined Google/DoubleClick will play if the proposed acquisition is consummated. She said she determined that the two companies product markets overlap in key ways that could substantially lessen competition down the road.

Rivals such as Microsoft have challenged the merger, complaining that it would give Google an unfair advantage in search and publisher-based advertising tools.

Google, in its response to the FTC ruling, cited the mergers potential benefits for consumers. The FTCs strong support sends a clear message: this acquisition poses no risk to competition and will benefit consumers, said Eric Schmidt, Googles chairman and CEO. We hope that the European Commission will soon reach the same conclusion, and we are confident that this deal will deliver more relevant ads for consumers, more choices for advertisers, and more opportunities for website publishers.

On Wednesday, Microsoft and entertainment media giant Viacom announced a $500 million advertising agreement that Google cited as evidence of a highly competitive market for online ads.

The search titan said it cannot formally close its DoubleClick acquisition until it gets clearance from European regulators, who are expected to announce their findings on April 2. The Australian Competition and Consumer Commission approved the deal in October.