WASHINGTON (AP) — Google is confronting a threat to its dominant search engine as federal regulators launch an attempt to dismantle its internet empire in the biggest U.S. antitrust trial in a quarter century. Over the next 10 weeks, federal lawyers and state attorneys general will try to prove Google rigged the market in its favor by locking its search engine in as the default choice in a plethora of places and devices. On Tuesday, prosecutors opened their case by saying it’s about the future of the internet and whether Google’s search engine will ever face meaningful competition. Google is arguing that competition from Microsoft’s Bing, Amazon and Yelp keep the marketplace fair.