Canada’s Competition Tribunal, the Competition Bureau watchdog, said it seeks to end Google’s dominance and anticompetitive practice, and restore competition in the country’s online advertising marketplace.

The notice, filed Thursday, asks the tribunal to force Google to sell two crucial pieces of advertising-market software and pay a fine of as much as 3% of the company’s global revenue.

“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 Wall Street Journal reported, citing the Competition Bureau’s  notice.

Google’s near-total control of the ad-tech was premeditated, the notice stated, rather than “superior competitive performance or happenstance.”

The Canadian lawsuit is the latest legal antitrust challenge for Google. The company is struggling with a U.S. federal judge’s ruling last August that the company engaged in illegal practices to preserve its search-engine monopoly. It could be forced to sell its browser Chrome and operating system Android, and pay a fine.

Google Vice President of Global Advertising Dan Taylor told the WSJ that the complaint filed by Canada’s antitrust watchdog “ignores the intense competition where ad buyers and sellers have plenty of choice,” and that the company looks forward to making its case in court.  

The Competition Bureau estimates Google holds a 90% market share in publisher ad servers, 70% in advertiser networks, 60% in demand-side platforms (DSP) and about 50% in advertisement exchanges.