Google closed on its $3.1 billion acquisition of DoubleClick this morning a couple of hours after the European Commission, as expected, waved the hackles-raising merger through.

US authorities blessed the merger in December.

The EC said the merger was “unlikely” to harm consumers either in ad serving or the intermediation of online advertising markets and so wasn’t anticompetitive.

According to the European regulators, the two companies aren’t in the same business and so aren’t competitors.

“Even if DoubleClick could become an effective competitor in online intermediation services,” it said, “it is likely that other competitors would continue to exert sufficient competitive pressure after the merger. The Commission therefore concludes that the elimination of DoubleClick as a potential competitor would not have an adverse impact on competition in the online intermediation advertising services market.”

The EC also threw out the argument that Google by controlling DoubleClick’s tools could raise the cost of ad serving for rival intermediaries and that the Google’s dominance in search could force DoubleClick’s tools on search ad buys.

And it decided that the Google + DoubleClick combine wouldn’t be so powerful that it could marginalize competitors because of the existence of other players like Microsoft, Yahoo and AOL.

Microsoft, Yahoo and others had of course objected to the merger on all these grounds.

The privacy issues raised about the merger by privacy advocates weren’t part of the EC’s consideration during its extended review.

In its statement this morning, the EC merely noted that “GoogleClick” had privacy obligations under European law.

Those regulations may get tightened up if the privacy forces get their way.