The European Commission has opened an antitrust investigation against Google for claims of unfair practice on search engine results. Price comparison sites like Foundem and Ciao have both submitted claims against Google for penalizing them on their search engine results, according to the Telegraph.

The investigation comes under the Lisbon Treaty’s “abuse of dominant position” powers and is the first time that Google has been targeted by the European Union.

Telegraph.co.uk can reveal that the Commission has written to Google with a series of questions over how its search functions operate and also questioned the way it sells advertising. It acted after complaints from the UK search site Foundem, a price comparison site, Ciao, an online shopping site owned by Microsoft, and ejustice.fr, a French site which details legal cases and solicitor services.