Seven & I Holdings, the Japanese convenience store chain operator valued at about $31 billion, has received a buyout proposal from Canadian convenience-store operator Alimentation Couche-Tard in what would be the largest-ever foreign takeover of a Japanese company if realized.

The "confidential, preliminary” offer will be examined by an independent committee and the board of directors has made no determination at this time whether to accept or reject it, the retailer said in a statement Monday, following a report on the bid by the Nikkei newspaper.

Neither offered details on the value of Couche-Tard's offer.

Shares in the Japanese company jumped as much as 22.7% in Tokyo on Monday, their largest gain on record.

Seven & I has come under pressure from activist fund ValueAct Capital Management over perceptions that its assets are worth more than the company is capitalizing on. In reaction, it has taken restructuring measures and initiated a buyback after fending off efforts to oust Chief Executive Officer Ryuichi Isaka.

ValueAct previously pushed the Japanese retailer to narrow its business 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.

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

Globally, its empire spans 85,000 convenience stores, gasoline stations and retail outlets.

Couche-Tard, with a market value of 80 billion Canadian dollars ($58.5 billion), operates convenience stores globally under its own brand, as well as Circle K and Ingo.

"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. "But knowing the Seven & I management, you can bet on them resisting this if the price is lower.”

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, I think the probability of something happening is quite slim,” Kato said.