TOKYO, March 4, 2025 (BSS/AFP) - Shares of the owner of 7-Eleven plunged on Tuesday after a report said the Japanese retailer plans to reject a multibillion-dollar takeover offer by Canada's Alimentation Couche-Tard (ACT).

Seven & i, which operates some 85,000 convenience stores worldwide, last year rebuffed an ACT offer worth nearly $40 billion that would have been the biggest foreign buyout of a Japanese firm.

The Yomiuri daily reported that a special committee scrutinising ACT's raised offer of reportedly around $47 billion has decided formally to say no to that too.

The decision was due in part to antitrust concerns, given Seven & i and ACT's overlapping network of stores in the United States, the daily added.

Seven & i shares, which have been highly volatile since ACT's approach was first announced, shed as much as 10 percent after the Tokyo market opened on Tuesday.

The latest news followed separate reports that the 7-Eleven owner is set to replace its CEO Ryuichi Isaka with outside director Stephen Hayes Dacus.

Dacus, who has also worked for Uniqlo owner Fast Retailing and the Japanese arm of US retail giant Walmart, would also be Seven & i's first foreign CEO.

Seven & i said on Monday "no decision has been made" about management changes.

Last week Seven & i said its founding family failed to put together sufficient financing for a buyout to fend off ACT's offer.

The franchise began in the United States, but it has been wholly owned by Seven & i since 2005 and is the world's biggest convenience store brand.

ACT, which began with one store in Quebec in 1980, now runs nearly 17,000 convenience store outlets worldwide including the Circle K chain.