WASHINGTON (AP) — The District of Columbia has sued Amazon, accusing the online retail giant of illegal anticompetitive practices in its treatment of sellers on its platform. The practices have raised prices for consumers and stifled innovation and choice in the online retail market, the DC attorney general alleges in an antitrust suit. The suit maintains that Amazon has fixed online retail prices through contract provisions and policies it applies to third-party sellers on its platform. It alleges these provisions and policies prevent sellers that offer products on Amazon.com from offering their products at lower prices or on better terms on any other online platform, including their own websites.