The European Commission said Wednesday it had opened an investigation into Google's job search tool on competition grounds, having identified a conflict of interest.
The move is the latest in a string of EU probes of the US giant's business practices, which have already led to billions of euros in fines.
The Commission will seek to determine if the group is giving its own jobs listing platform a priority over competitors within Google search results.
A Commission spokeswoman said a "preliminary investigation is ongoing" into the job search tool.
The Commission can open a formal procedure if it finds sufficient evidence against Google, which could see the digital giant fined a fourth time for what Brussels deems an excessively dominant market position.
Speaking in Berlin on Tuesday, EU Competition Commissioner Margrethe Vestager said the issue needed to be addressed on competition grounds.
"There's an obvious conflict of interest here, an obvious temptation to adjust the way the platform works, to favour their own services ahead of others," she said.
A similar situation existed in July 2017 when the EU fined the Californian giant's "Google Shopping" service 2.42 billion euros ($2.7 billion) for using its search engine to favour its own comparison shopping service.
"We?re looking right now at whether the same thing may have happened with other parts of Google?s business -? like the job search business known as Google for Jobs," said Vestager.
A Google spokesman told AFP Wednesday: "Since launch (of Google for Jobs), we've made a number of changes to address feedback in Europe.
"Finding a job can be tough, so we worked with jobs providers to create a better experience," he added.
The Commission spokeswoman commented on earlier probes of Google services, saying that "what the Commission has found is that those different specialised services have some things in common -- but they also have important differences.
"We need to look individually at each" of them, she added.
In July 2018, the EU fined Google 4.34 billion euros for antitrust violations with its Android operating system for smartphones.
And in March it fined Google 1.49 billion euros over search-advert restrictions for third-party websites on its AdSense advertising service.