In January Google said it was consolidating its services' privacy policies into one single policy across all of its sites, including Google+, Gmail and YouTube.
The EU regulators, data protection representatives from each of the 27 member states, wrote a letter to Google Chief Executive Larry Page, ZDNet reported Friday.
"We wish to check the possible consequences for the protection of the personal data of these citizens in a coordinated procedure.
"In light of the above, we call for a pause in the interests of ensuring that there can be no misunderstanding about Google's commitments to information rights of their users and EU citizens, until we have completed our analysis," it said.
Google, for its part, said it was surprised by the action.
"We briefed most of the members of the [regulators'] working party in the weeks leading up to our announcement," said Al Verney, Google's spokesperson in Brussels.