In a written response to the Competition Bureau’s lawsuit over Google’s advertising practices in Canada, the tech giant denied abusing its market power, which it argued is not “substantial.”

As previously reported, the Competition Bureau is suing Google over alleged anticompetitive conduct in its online advertising business.

According to the Bureau, an investigation into the company found that, in Canada, “Google is the largest provider across the ad tech stack for web advertising and has abused its dominant position through conduct intended to ensure that it would maintain and entrench its market power.”

However, Google says the bureau’s claim that it unlawfully tied together its ad tech tools is false.

The tech company owns four of the largest online ad technology services used in Canada: DoubleClick for Publishers, AdX, Display & Video 360 and Google Ads. The bureau estimated that Google holds about 90% market share in publisher ad servers, 70% in advertiser networks, 60% in demand-side platforms and 50% in ad exchanges.

The Bureau wants Google to sell off DoubleClick and AdX, and pay a penalty. However, in its response, Google maintained that the penalty proposed, which would be equal to three times the value of the benefit it derived from anticompetitive practices or 3% of Google’s worldwide gross revenues, would be unconstitutional.

“The very threat of such a fine will diminish or negate the incentives of Google, Google Canada and many other businesses to invest and innovate, thus undermining consumer welfare,” it said.