Google Inc's planned takeover of rival DoubleClick for $3.1 billion would harm European citizens through greater intrusion of privacy, the EU's top consumer lobby BEUC said on Thursday.

The Google/DoubleClick merger would harm consumer welfare by creating a structure that almost certainly will be less respectful of user privacy, BEUC said in a letter to the European Commission this week.

Last month, the European Union's executive European Commission -- the bloc's top competition watchdog -- opened an in-depth probe into the proposed takeover, saying it would raise competition concerns in online advertising.

Google, which uses consumer queries to choose advertisements which appear on Web surfers' screens, wants to buy DoubleClick to increase its clout in tailoring advertisements to consumer activities.

Post merger, Google will have the ability and incentive to engage in significantly more intrusive user tracking and profiling than exists today, BEUC said.

The lobby group also said that the merger would place the online advertising market in jeopardy because the combined company will dominate both major pipelines for online advertising -- for search ads and non-search ads.

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

The higher prices for advertisements would likely be passed on to consumers, the lobby group said.

The Commission has until April 2, to take a final decision on whether the proposed transaction would significantly impede effective competition.

(Reporting by Huw Jones; Editing by Quentin Bryar)