Seven & I, the Japanese owner of 7-Eleven, announced on Thursday a raft of measures to fend off a takeover by a Canadian rival, including a $13.2-billion share buyback and an initial public offering of its U.S. unit.

The announcements are the latest twist in a saga that began last year when Seven & I rebuffed a takeover offer worth nearly $40 billion from Canada's Alimentation Couche-Tard.

Seven & I, which operates some 85,000 convenience stores worldwide, also named Stephen Hayes Dacus as its first foreign chief executive.