TOKYO (Reuters) - Canada's Alimentation Couche-Tard is discussing how much it could raise the offer price to buy Japan's Seven & i Holdings, Bloomberg News reported on Thursday, citing unnamed sources familiar with Couche-Tard's internal talks.

Couche-Tard earlier this week said it was willing to continue the buyout talks after Seven & i rejected its $38.5 billion offer.

Couche-Tard must offer a significantly higher price than the initial proposal to get Seven & i to enter negotiations, but whether the suitor will submit another proposal to Seven & i remains uncertain, Bloomberg reported citing the sources.

Seven & i has tapped Nomura to advise its board in preparation for a potential takeover battle with Couche-Tard, the Financial Times separately reported on Thursday.

Shares in Seven & i had risen more than 4% as at the end of morning trade on Thursday.

Couche-Tard has said it was confident of arranging financing for the deal, which would be the largest-ever foreign takeover of a Japanese company.

Seven & i last week said the deal was not in the best interests of its shareholders and could face antitrust challenges in the U.S., where the combined company would be the biggest convenience store operator by a considerable margin.