Remove roots, outer leaves and tops from leeks, leaving only white part. Cut white part in half lengthwise. Cut crosswise into 1/2-inch- thick slices to measure 1 cup. Rinse with cold water; drain.
Microwave potatoes as directed on package. Meanwhile, in 3-quart saucepan, cook bacon until crisp; drain on paper towels. Crumble bacon; set aside. Cook leeks in bacon drippings over medium heat 3 minutes, adding 2 tablespoons of the broth to prevent sticking. Cook 4 minutes longer, stirring occasionally, until tender.
Stir in remaining broth, scraping pan to loosen brown particles. Stir in potatoes and salt. Gradually add milk, stirring until smooth. Cook uncovered 10 minutes, stirring occasionally, until thoroughly heated. Stir in pepper. Sprinkle individual servings with bacon.