A major Canadian convenience store operator says it is disappointed that Japanese retail giant Seven & i Holdings has rejected its takeover offer, but it remains willing to negotiate.

Alimentation Couche-Tard issued a statement on Sunday, after the owner of 7-Eleven said in a letter on Friday that the offer "grossly undervalues" the global convenience store chain.

The statement says, "Given the mutual benefits of a combination, we are disappointed in 7&i's refusal to engage in friendly discussions."

The Canadian firm, which operates convenience stores and gas stations around the world, suggested that it can afford to raise the bid price.

The statement notes, "We are highly confident that we have sufficient capacity to finance the transaction in cash and that financing would not be a condition to closing a transaction."

The document also referred to Seven & i pointing out that the merger would pose significant regulatory challenges under US competition law.

The Canadian firm said it would consider divesting assets to secure regulatory approvals.