1Cook wild rice as directed on package.
2Meanwhile, in 3-quart saucepan, melt butter over medium heat. Add celery, onion and mushrooms; cook about 5 minutes, stirring occasionally, until crisp-tender.
3Stir in flour, sugar and pepper. Stir in cooked wild rice, broth, ham and Worcestershire sauce; cover and simmer 10 minutes over medium heat. Stir in yogurt; heat just until hot (do not boil).