A man walks past a logo of Google in front of at an office building in Zurich, Switzerland July 1, 2020. Photo: Reuters
The "Choice Screen" feature allows users to choose their default search engines during the initial set up of their new Android device.
COMCO said Google had removed this feature in Switzerland, even though it remained available in other countries in Europe.
As a result, the Google search engine is imposed as the default option for Swiss users.
Google said it was aware of the investigation. "We look forward to cooperating fully with the authority to address their questions," a spokesperson said.
In digital markets, default settings play a decisive role, COMCO said, with the removal of the option limiting the visibility of other search engines competing with Google when users set up their devices.
"This new practice by Google could affect the ability of search engine providers and, more broadly, other digital service providers to compete," COMCO said.
"It also creates an unequal treatment between Swiss users and those in the European Economic Area," it added.
The preliminary investigation will determine whether there were any indications of unlawful competition under the Swiss Cartel Act.
Google has a dominant position in the Swiss online market, holding 82% of the search market in the country, according Statcounter, a web analytics company.
