The reputation of Alimentation Couche-Tard as a disciplined investor suggests the acquisitive Canadian convenience retailer will think long and hard whether it will sweeten its $8.6 billion offer for Australian target Caltex.

While Caltex on Tuesday pushed the door half-open for its suitor, Couche-Tard - French for "night owl" - is still considering whether its offer of access to "selected non-public information" will allow it to take the matter further, far less raise its tentative $34.50 a share offer as suggested by the Sydney-based player.