The Federal Trade Commission, in a 4-to-1 vote, allowed Google's purchase of DoubleClick to go ahead. Thus a 8-month antitrust investigation has come to an end and the $3.1 billion deal will be closed.

"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," the FTC said. The commissioners promised to keep a close eye on Google and act swiftly if the company engages in anti-competitive practices.

Commissioner Pamela Jones Harbour dissented and wrote a 13-page explanation, which argues that the Google-DoubleClick deal will significantly transform the market.

A political controversy over deleted documents and conflicts of interest among online rights groups have drawn recently a lot of criticisms to the proposed Google-DoubleClick deal. The European Union is analyzing how the $3.1 billion acquisition would impact competitiveness in the online advertising arena.

Also, a EU civil liberties panel has asked Google and online advertisement company DoubleClick to testify in matters of privacy on January 21 or January 31. The U.S. Senate held similar hearings in September, this year. The EU and plans to wrap up its investigation into the deal by April 2.

“The FTC's strong support sends a clear message: This acquisition poses no risk to competition and will benefit consumers,” Google Chief Executive Officer Eric Schmidt said in a statement. “We hope that the European Commission will soon reach the same conclusion.”

“I do not doubt that this merger has the potential to create some efficiencies, especially from the perspective of advertisers and publishers. But it has greater potential to harm competition, and it also threatens privacy,” said Harbour.