Cardtronics, which claims to be the world’s largest operator of ATMs, began developing its own proprietary ATM transaction processing network in 2006. In addition to the Circle K ATMs, the firm currently processes transactions for 14,000 Cardtronics-operated ATMs.

All remaining Cardtronics ATMs will reportedly transition to Cardtronics’s in-house processing network during 2008. Cardtronics noted that it operates over 31,600 ATMs in every major US market as well as approximately 2,000 ATMs throughout the UK and over 1,000 ATMs in Mexico.

Major energy industry clients include 7-Eleven, BP Amoco, Chevron, ExxonMobil, Hess and Sunoco.