The European Commission has launched an investigation into Google after other search engines complained that the firm had abused its dominant position.
The body said it would look into whether the world's largest search engine lowered the ranking of competing services in its results.
The probe follows complaints by British price comparison site Foundem and French legal search engine ejustice.fr.
Google said it would work with the Commission to "address any concerns".
Earlier this year the attorney general of Texas launched a similar investigation following complaints from firms including Foundem.
The complaints in both cases are from competitors which allege that Google manipulates its search results.
"The European Commission has decided to open an antitrust investigation into allegations that Google has abused a dominant position in online search," the Commission said.
It said the action followed "complaints by search service providers about unfavourable treatment of their services in Google's unpaid and sponsored search results coupled with an alleged preferential placement of Google's own services."
The Commission's investigation does not imply any wrongdoing by Google.
"Since we started Google we have worked hard to do the right thing by our users and our industry," said the firm in a statement.
"But there's always going to be room for improvement, and so we'll be working with the Commission to address any concerns."
The body said it would look into whether the world's largest search engine lowered the ranking of competing services in its results.
The probe follows complaints by British price comparison site Foundem and French legal search engine ejustice.fr.
Google said it would work with the Commission to "address any concerns".
Earlier this year the attorney general of Texas launched a similar investigation following complaints from firms including Foundem.
The complaints in both cases are from competitors which allege that Google manipulates its search results.
"The European Commission has decided to open an antitrust investigation into allegations that Google has abused a dominant position in online search," the Commission said.
It said the action followed "complaints by search service providers about unfavourable treatment of their services in Google's unpaid and sponsored search results coupled with an alleged preferential placement of Google's own services."
The Commission's investigation does not imply any wrongdoing by Google.
"Since we started Google we have worked hard to do the right thing by our users and our industry," said the firm in a statement.
"But there's always going to be room for improvement, and so we'll be working with the Commission to address any concerns."
