By Nathalie Tadena Sandwich chain Quiznos Corp. named Stuart K. Mathis as its new president and chief executive, succeeding Greg MacDonald, who is stepping down immediately. Mr. Mathis's appointment is effective July 30. Mr. Mathis most recently served as president of United Parcel Service Inc.'s (UPS) UPS store network, a position he held for 10 years. He has also held executive roles at Mail Boxes Etc., the predecessor brand to the UPS store, and Domino's Pizza (DPZ). The company also appointed Susan Lintonsmith as its new chief marketing officer, a position she previously held at Red Robin Gourmet Burgers Inc. (RRGB). In February, the company named Harsha V. Agadi, the former chairman and CEO of Friendly's, as executive chairman. Mr. Agadi said Thursday that Mr. Mathis' experience in retail, restaurants and franchising "uniquely qualifies him" to lead the company. Quiznos in January reached a deal with debt holders that gave control to Avenue Capital Group, helping it avoid bankruptcy. Write to Nathalie Tadena at nathalie.tadena@dowjones.com Subscribe to WSJ: http://online.wsj.com?mod=djnwires