The board of the Casey’s Convenience store chain has turned down a proposed buyout 7-Eleven. The Ankeny-based Casey’s board had originally been offered a buyout of $40 a share, and later received a revised offer that upped the bid to $43 a share.

But a news release from Casey’s says the board has “unanimously determined that the revised proposal does not reflect the value of Casey’s and its significant growth opportunities, and is not in the best interests of the Casey’s shareholders.”

The release says since the two companies have been unable to reach mutually agreeable terms, they are no longer in discussions. Seven-Eleven is owned by a Japanese company. Casey’s has around 1,500 stores.