Shares in the Japanese owner of 7-Eleven surged Wednesday following reports that Canada's Alimentation Couche-Tard (ACT) had hiked its takeover offer by almost 20 percent. But Bloomberg News and Japan's Nikkei business daily reported Wednesday that ACT, which owns the Circle K brand, had upgraded its offer to $18.19 per share, or a total of around seven trillion yen ($47.2 billion).

Shares in the Japanese owner of 7-Eleven surged Wednesday following reports that Canada's Alimentation Couche-Tard (ACT) had hiked its takeover offer by almost 20 percent. But Bloomberg News and Japan's Nikkei business daily reported Wednesday that ACT, which owns the Circle K brand, had upgraded its offer to $18.19 per share, or a total of around seven trillion yen ($47.2 billion).

Alimentation Couche-Tard has reportedly offered to pay over $47bn for the Japanese-owned retail giant.

In Japan more is at stake than money in the mammoth takeover battle for 7-Eleven, the world's biggest convenience chain, by Canadian retail giant Alimentation Couche-Tard. But the Canadian group, which owns Circle K and runs nearly 17,000 outlets worldwide, has vowed to pursue what would be the biggest foreign takeover of a Japanese firm.