OTTAWA (Reuters) -Canada's Competition Bureau is suing Alphabet's Google over alleged anti-competitive conduct in online advertising, the antitrust watchdog said on Thursday.

The Competition Bureau, in a statement, said it had filed an application with the Competition Tribunal seeking an order that, among other things, requires Google to sell two of its ad tech tools. It is also seeking a penalty from Google to promote compliance with Canada's competition laws, the statement said.

Google said the complaint "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," Dan Taylor, VP of Global Ads, Google said in a statement.

The Competition Bureau opened an investigation in 2020 to probe whether the search engine giant had engaged in practices that harm competition in the online ads industry, and expanded the probe to include Google's advertising technology services earlier this year.

The investigation found that Google is the largest provider across the ad tech stack for web advertising in Canada and it "has abused its dominant position through conduct intended to ensure that it would maintain and entrench its market power," the bureau said on Thursday.

The case follows the U.S. Justice Department's effort to show Google monopolized markets for publisher ad servers and advertiser ad networks.

Google has argued that the U.S. DOJ is ignoring the company's legitimate business decisions and that the online advertising market is robust. The company also says the U.S. government had cherrypicked a narrow slice of the online market and did not account for aggressive competition.

The closing arguments in the U.S. case were made on Monday.

Earlier this year, Google offered to sell the ad exchange to end an EU antitrust investigation but European publishers rejected the proposal as insufficient, Reuters first reported in September.