COOK potatoes in boiling broth in large covered saucepan 15 min., stirring after 8 min. Uncover; simmer 5 to 6 min. or until potatoes are tender and most of broth is absorbed.
STIR in cream cheese spread; mash potatoes slightly on low heat until cream cheese is melted. Add sour cream and Parmesan; mash and stir until potatoes are smooth and heated through.