Alphabet's Google plans to appeal against the "adverse" portion of the court decision in the US Department of Justice’s monopoly case against the technology giant.

On Thursday US District Judge Leonie Brinkema found Google liable for "willfully acquiring and maintaining monopoly power" in markets for publisher ad servers and ad exchanges.

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Publisher ad servers are platforms used by websites to store and manage their digital advertising inventory. Along with ad exchanges, the technology allows news publishers and other online content providers make money by selling advertising.

The judge also ruled that Google illegally dominates two markets for online advertising technology.

The company said on Friday that the judge had issued a mixed decision, where she ruled that the DOJ failed to show that Google’s advertiser tools or acquisitions of DoubleClick and AdMeld were anticompetitive but that Google’s publisher tools violated antitrust laws by excluding rivals.

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The DOJ had said that Google should have to sell off at least its Google Ad Manager, which includes the company's publisher ad server and ad exchange.