Investing.com -- Alphabet's Google lost its legal battle against Department of Justice after a U.S. Federal Judge ruled Monday that the internet search engine illegally maintained a monopoly in the online search and text advertising markets.

“Google is a monopolist, and it has acted as one to maintain its monopoly,” Judge Amit Mehta in Washington ruled on Monday.

The judge concluded that Google has "violated Section 2 of the Sherman Act by maintaining its monopoly in two product markets in the United States general search services and general text advertising-through its exclusive distribution agreements."

The ruling, which can be appealed, marked a major win for the DoJ, who had argued that Google's agreements with companies including Apple (NASDAQ: AAPL) and others to make Google search default search engine on smartphones violated antitrust laws.

Alphabet and the DoJ didn't immediately respond to Investing.com's request for comment.

Alphabet Inc Class A (NASDAQ: GOOGL) was down 7% in recen trade.