Clothing giant Jones Apparel Group Inc on Thursday named Heather Pech president of its Polo Jeans Co unit and expanded the roles of two other key executives. The New York-based company, whose brands include Jones New York, Evan-Picone, Gloria Vanderbilt, Erika and lei, said Pech was most recently group president of Jones New York Sport, Jones Jeans, Easy Spirit, Jones Studio and Rena Rowan.