Valued at the equivalent of $31 billion before news of the offer emerged, Seven & i shares jumped 23% on Monday. The company said the bid was preliminary and non-binding, without disclosing terms. A special committee of independent outside directors will make a “prompt, careful and comprehensive review of the proposal,” Seven & i said in a statement Monday.

Although Couche-Tard is smaller than Seven & i, with about 14,000 stores compared with more than 85,000 for the Japanese retailer, the Canadian company enjoys a bigger valuation of about $58.5 billion. Foreign takeovers of Japanese companies are extremely rare, but recent changes in guidelines for merger and acquisition proposals, and activist investors pushing companies to boost value—including at Seven & i—could boost the odds of a deal that would create a global convenience-store behemoth.

“It all depends on the price, and I guess the weak yen has made it more attractive and anything north of ¥7 trillion, the management would have a tough time rejecting,” said Amir Anvarzadeh, a strategist at Asymmetric Advisors Pte. “But knowing the Seven & i management, you can bet on them resisting this if the price is lower.” 

Shares of Seven & i posted their largest gain on record following a report on the bid by the Nikkei newspaper, which the company later confirmed. Neither offered details on the value of Couche-Tard’s offer. Before today’s jump, the stock had dropped 21% since the end of February, making the company more attractive to a possible suitor.

Seven & i has come under pressure from activist fund ValueAct Capital Management LP over perceptions that its assets could be worth more and to narrow its focus to 7-Eleven stores, saying that as a standalone listed company the convenience-store business could be worth as much as ¥8,500 per share. Seven & i shares closed at ¥2,161 Monday. 

In reaction, it’s taken restructuring measures and initiated a buyback after fending off efforts to oust Chief Executive Officer Ryuichi Isaka. Although headquartered in Tokyo, Seven & i gets the majority of its revenue from overseas. Last fiscal year, 74% of sales came from North America compared with 25% from Japan.  

Couche-Tard, Canada’s most valuable retailer, operates convenience stores around the world under its own brand, as well as Circle K and Ingo. It has a history of expansion overseas, and bought almost 2,200 gasoline stations in Europe from TotalEnergies SE for €3.1 billion last year. It previously made a $20 billion bid to buy Carrefour SA, which was blocked by the French government. 

Couche-Tard’s balance sheet itself may not be strong enough to sustain a strong cash offer, said Mio Kato, an analyst at LightStream Research.

“I don’t think Seven & I would want to sell and without an attractive cash offer,” Kato said. “The probability of something happening is quite slim.”

Any merger of the companies, the two biggest convenience-store operators in North America, could invite scrutiny from competition regulators. Seven & i operates more than 13,000 stores in the US and Canada, including Speedway outlets that it acquired in recent years, while Couche-Tard has almost 9,000. 

While best known for its 7-Eleven stores, the company’s operations also include Denny’s Corp.’s Japan restaurants, the Ito-Yokado supermarket chain and its own bank. 

Although American in origin, the convenience store concept turned out to be transformational for the Japanese company, which fully took over the chain in 2005 in the US and embraced it as part of its name. Over the years, 7-Eleven evolved into a franchise offering affordable food, beverages and daily goods, as well as municipal and delivery services. 

Isaka has spent more than $25 billion expanding Seven & i’s global foot print, especially in the US, where he added the Speedway and Sunoco gasoline-station networks. In an interview with Bloomberg News earlier this year, he said Seven & i would be interested in making its own acquisitions.

“If there’s an opportunity, we’d proactively consider M&A,” Isaka said in January.