Dillard's, Dunkin' Brands, Sheetz and Wakefern Food Corp have also come on board the Merchant Customer Exchange (MCX) venture, joining big hitters such as 7-Eleven, Target and Wal-mart.

MCX is already building what it promises will be a versatile mobile-commerce system, initially focusing on integration between payments and offers.

The consortium is taking on a slew of major players, including Google Wallet, the soon-to-launch telco-led consortium Isis, PayPal and Square.

Dodd Roberts, MCX, says: "Merchants recognise mobile payment adoption will be limited until it can be used where consumers regularly shop. MCX offers unmatched scale, representing merchants with more than $1 trillion in annual sales across nearly every merchant vertical."