San Francisco, Feb 6 (IANS): Google will face another antitrust trial in the US, this time over its ad tech policies. The ad tech trial will begin in the US state of Virginia from September 9.

In January last year, the US Department of Justice (DOJ) claimed that Google violated US antitrust law by illegally monopolising the digital ads market.

"Google's anticompetitive behaviour has raised barriers to entry to artificially high levels, forced key competitors to abandon the market for ad tech tools, dissuaded potential competitors from joining the market, and left Google's few remaining competitors marginalised and unfairly disadvantaged," the lawsuit said.

Filed in the US District Court for the Eastern District of Virginia, the complaint alleged that Google monopolises key digital advertising technologies, collectively referred to as the "ad tech stack," that website publishers depend on to sell ads and that advertisers rely on to buy ads and reach potential customers.

As alleged in the complaint, over the past 15 years, Google has engaged in a course of anticompetitive and exclusionary conduct that consisted of neutralising or eliminating ad tech competitors through acquisitions; wielding its dominance across digital advertising markets to force more publishers and advertisers to use its products; and thwarting the ability to use competing products.

"In doing so, Google cemented its dominance in tools relied on by website publishers and online advertisers, as well as the digital advertising exchange that runs ad auctions," the complaint said.

Google has said the DOJ's reasoning "would slow innovation, raise advertising fees and make it harder for thousands of small businesses and publishers to grow".

The ad tech trial will be Google's second fight against the DOJ in an antitrust case, following a trial over its search business beginning last September.