Convenience store operator 7-Eleven Inc. is the mystery bidder for Casey’s General Stores Inc. trying to top a Canadian rival, according to a published report.

Casey’s rejected the latest bid by Alimentation Couche-Tard (ALL-ee-men-tass-e-yone koosh-tard) Inc. on Tuesday and said at the time it had received a bid for $40 from an unnamed party.

The chain said that bid — worth $2.03 billion — was too low but it agreed to further talks with the suitor.

The Wall Street Journal, citing sources familiar with the deal it did not identify, says 7-Eleven is the company making the bid.

7-Eleven and Casey’s declined to comment on the report.

Last week, Couche-Tard raised its offer to $38.50 per share in cash from $36.75.

Casey’s is based in Ankeny, Iowa.