The Belgian Competition Authority (the BCA) announced today the opening of an investigation into Google. The BCA suspects Google of abusing its dominant position in the online advertising sector, in breach of Article 102 of the Treaty on the Functioning of the European Union and Article IV/2 of the Belgian Code of Economic Law.

The BCA takes issue with the general terms and conditions of use applicable to specific Google intermediation services. Advertisers wishing to promote their products online connect with publishers monetising advertising space on their websites through intermediation services.

The BCA suspects Google of supplying its intermediation services in a discriminatory manner. While the BCA does not explicitly say which service is concerned, its press release refers to Google’s ad exchange service AdX, which is a marketplace where publishers and advertisers buy and sell digital ad inventory in an open auction, and to Google’s Ad Buying Tools, which allow advertisers to purchase advertising space.

This is not the first time that Google comes in the crosshairs of competition authorities in Europe. Google has already been fined four times by the European Commission, including in relation to its online advertising business.

As recently as 5 September 2025, the European Commission fined Google EUR 2.95 billion for distorting competition in the advertising technology industry by favouring its own online display advertising technology services to the detriment of providers of competing services, advertisers and online publishers. Google has appealed this decision (Case T-794/25, currently pending).

It is striking that the BCA has now decided to prosecute conduct which presumably exceeds the Belgian borders and would therefore seem to be a candidate for Commission review. The BCA explains its approach by stating that the digital sector features among its enforcement priorities.