Canada's antitrust regulator is suing Alphabet's Google (GOOGL) over alleged anti-competitive conduct in its online-advertising business, in the latest regulatory challenge to the tech giant's dominance.

Canada's Competition Bureau said in a notice it filed Thursday with the Competition Tribunal, where the case will be argued, that Google "locks market participants into using its own ad tech tools," and is pushing for the company to sell two of its ad tech tools.

The Canadian antitrust watchdog also seeks an order that "directs Google to pay a penalty to promote compliance with the Competition Act," and prohibits the firm "from continuing to engage in anticompetitive practices."

The lawsuit comes after the U.S. Department of Justice (DOJ) said last week that Google should sell off its Chrome browser, following an 澳洲幸运5官方开奖结果体彩网:August court ruling ꦗ;that the tech firm holds an illegal monopoly in search.

Google Says Preparing for Court Response

Google's vice president of global advertising, Dan Taylor, said in a statement to Investopedia that the Canadian allegation "ignores the intense competition where ad buyers and sellers have plenty of choice and we look forward to making our case in court."

Alphabet shares fel🦋l less than 1% soo𓄧n after markets opened Friday but are up 20% this year.