SAN FRANCISCO (AP) — Burger King is expanding its delivery service to three new metropolitan areas — Chicago, Los Angeles and San Francisco. The Miami-based chain first rolled out delivery in Washington, D.C., early last year and now offers it in the Houston, Miami and New York areas as well. The delivery push comes as competition intensifies in the fast-food industry, with McDonald's, Taco Bell and Wendy's all fighting for customers with new menu offerings and stepped-up advertising.