Sundar Pichai, CEO of Google, speaks to the media before the opening of the Berlin representation of Google Germany in Berlin on January 22, 2019.

Google fired about half a dozen of its largest lobbying firms as it gears up to face antitrust regulators, The Wall Street Journal reported Wednesday.

The move is part of a broader shake-up of Google's global government affairs and policy operations, according to the Journal. Within a matter of months, sources told the Journal, Google has restructured its policy team at the nation's capital and lost two senior officials who helped build the operation. The firms Google dropped represent about half of Google's $20 million annual lobby bill, according to the report.

Google did not immediately respond to CNBC's request for comment.

The upheaval comes after reports that the Justice Department is preparing to investigate Google on antitrust grounds. The company previously agreed to change some of its practices in a 2013 settlement with the Federal Trade Commission, which had been concerned the company could stifle competition. Today, Google still controls more than 70% of the search engine market, according to NetMarketShare.

Google has already faced three hefty fines from regulators in Europe who say the company has violated antitrust law there. Most recently, the European Union ordered Google to pay the equivalent of roughly $1.7 billion for stifling competition in the online advertisement sector. In 2018, regulators in Brussels imposed a $5 billion fine on the company for abusing the dominant position of its Android mobile operating system. A year earlier, the EU fined Google $2.7 billion for using its search dominance to favor its shopping comparison service.

Antitrust regulation has become a key issue in the U.S. and a cornerstone of presidential candidates' platforms. Shares of Google parent company Alphabet, Facebook, Amazon and Apple all fell last week on reports that the DOJ and Federal Trade Commission were divvying up antitrust oversight of the four companies.

In a speech on Wednesday, the DOJ's Assistant Attorney General Makan Delrahim laid out some potential antitrust arguments against Big Tech firms and said providing low prices to consumers cannot absolve the sector of scrutiny.

Read more on The Wall Street Journal.

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