The European Parliament on Thursday approved a motion, stressing the need to prevent online companies from abusing dominant positions.
The resolution welcomed the European Commission's pledges to investigate further the search engines' practices, according to a press release on the Parliament's official website.
The resolution called on European Union (EU) member states and the Commission to break down barriers to the growth of the EU's digital single market. The lawmakers also called on the Commission to enforce EU competition rules and unbundle search engines from other commercial services.
It urged the Commission "to prevent any abuse in the marketing of interlinked services by operators of search engines", stressing the importance of non-discriminatory online search.
Indexation, evaluation, presentation and ranking by search engines must be unbiased and transparent, said the lawmakers.
The motion did not mention specific search engine company. However, media reports had that Google has been the subject of a four-year anti-trust investigation in Europe, which still has not reached a conclusion.