A major Canadian convenience store operator has reportedly raised its offer to acquire Seven & i Holdings. The Japanese retail giant is expected to review the new proposal in a special committee of only outside directors.

Bloomberg reported that Alimentation Couche-Tard raised its offer by about 20 percent to 47.2 billion dollars.

Sources say the Canadian operator of Circle K convenience stores made the new bid on September 19.

The previous proposal was about 39 billion dollars. Seven & i rejected that offer on September 6, saying it "grossly undervalues" the Japanese firm.

Seven & i added at the time that even if the price were raised, a merger of the top two convenience store operators in the US would face significant regulatory hurdles.