However, the deal still faces a challenge by the European Commission's Competition Unit and Google said it would not complete the takeover until it was cleared by the EU.

The commission's decision is expected by April 2 next year.

The EU's top consumer lobby, the BEUC, has that same concern and yesterday sent a letter to the European Commission warning that the merger would harm European citizens through greater intrusion of privacy.

BEUC wrote: "The Google/DoubleClick merger would harm consumer welfare by creating a structure that almost certainly will be less respectful of user privacy. Post merger, Google will have the ability and incentive to engage in significantly more intrusive user tracking and profiling than exists today.

"There are many ways in which Google, post-merger, could push up prices for advertisers."

BEUC added that the higher prices would most likely be passed onto consumers.