DALLAS, 2015-7-30 — /EPR Retail News/ — 7‑Eleven, Inc. (SEI), the world’s largest convenience retailer with 56,400 stores worldwide, has signed a master franchise agreement with Seven System Vietnam Co. Ltd. to develop and operate 7‑Eleven® stores in Vietnam. The expansion marks the company’s first stake in the Pacific Rim since 7‑Eleven entered Indonesia in 2009. 7‑Eleven’s…