The legal challenge in Canada adds to ongoing antitrust scrutiny Google faces in the US, where it is accused of manipulating search and ad markets to preserve its monopoly|Robert Scoble|CC BY 2.0

Canada’s competition watchdog is suing Google, alleging that the tech giant unlawfully built and maintained its dominance in the online advertising market.

The Competition Bureau claims Google’s actions, spanning years, were a deliberate effort to exclude competitors, stifle innovation and entrench its control over digital ad technology. 

The antitrust watchdog accused the company of illegally linking two advertising tools—AdX, its ad exchange, and DFP, its ad server, which are critical for buying and selling digital ads—to maintain dominance and distort ad auctions. It petitioned the Competition Tribunal, seeking Google’s sale of the tools.

It also seeks a fine of up to 3% of Google’s global revenue. Last year, advertisements (that you see next to search results) generated 57% of parent company Alphabet’s $307 billion in revenue.

The legal challenge adds to the company’s ongoing antitrust scrutiny in the US, where it is accused of manipulating search and ad markets to preserve its monopoly.

Google has 45 days to respond to the allegations.