Canada’s Competition Bureau is suing Google for alleged anti-competitive conduct in its online advertising.

In a statement, the country’s antitrust watchdog alleged Google had illegally linked two advertising tools to maintain market supremacy and used this dominant position to distort ad auctions by preferring its own tools.

The agency said it had filed an application with the Competition Tribunal, a court-like independent body, that would require Google to sell two of its ad technology tools.

In a statement Google said the complaint out of Canada “ignores the intense competition where ad buyers and sellers have plenty of choice and we look forward to making our case in court”.

“Our advertising technology tools help websites and apps fund their content, and enable businesses of all sizes to effectively reach new customers,” said Dan Taylor, vice-president of global advertising.

This case centers on online web advertisements - the ads shown to users while visiting other websites.

Digital ad inventory - the space website publishers make available for sale - is often bought and sold through automated auctions using digital platforms.

These platforms are known as ad tech tools, while the entire set of tools used through the purchasing process are known as the ad tech stack.

According to the Competition Bureau, an investigation found that Google had “abused its dominant position” as the biggest ad tech stack in Canada.

“Through a series of calculated decisions, taken over the course of multiple years, Google has excluded competitors and entrenched itself at the center of online advertising,” the Competition Bureau said in its notice announcing the suit of Thursday.

“Google’s near-total control of the ad-tech [software] is a function of premeditated design and conduct, rather than superior competitive performance or happenstance.”

The agency said it was asking the Competition Tribunal to force Google to sell two of its ad tech tools, and pay a fine of as much as 3% of the company’s global revenue “to promote compliance” with Canada’s competition laws.

Google has 45 days to file its response with the tribunal.