General Growth Properties Inc. (GGP) announced Sarah Alter has joined GGP as senior vice president of Corporate Marketing, and Erin Armendinger has joined as vice president of Customer Experience. Alter and Armendinger each bring two decades of respective marketing and consumer engagement experience to their new roles. As senior vice president of Corporate Marketing, Alter oversees the corporate marketing, creative services, events management, philanthropy and marketing budget disciplines within GGP.

Alter most recently served as vice president of Products & Services for Discover Financial Services. As vice president of Customer Experience, Armendinger oversees Same Day Delivery, GGP Gift Card and multi-channel retail functions within GGP. Armendinger's experience spans such retail institutions as Tiffany & Co.

and the Jay H. Baker Retailing Center at The Wharton School, where she served as managing director. While at Tiffany & Co., Armendinger held various roles in merchandising, strategy and business process improvements. Both Alter and Armendinger report to Senior Vice President Scott Morey.

In addition to Corporate Marketing and Customer Experience, Morey also oversees Information Services and Field Marketing.