A group of  leading U.S. retailers announced today they have formed Merchant Customer Exchange (MCX), a company dedicated to mobile-commerce with a mobile wallet app already under development.

MCX is currently composed of merchants like 7-Eleven, Best Buy, CVS/pharmacy, Darden Restaurants (Olive Garden, Red Lobster), Lowe’s, Target, Wal-Mart and others. All together the MCX merchants account for $1 trillion in annual sales, and the group expects to announce more members in the coming months. MCX intends to cater to the needs of financial institutions, merchants and consumers as mobile payments become more common.

Mike Cook, Wal-Mart’s corporate vice president and assistant treasurer said in a statement the MCX platform will use secure, efficient technology that will benefit all merchant categories including retail, dining, petroleum and e-commerce.

We’ve seen increased activity regarding mobile wallet and near field communication (NFC) technology recently, and the announcement of MCX is yet another example of big companies vying for position in the emerging sector.

Last week Mobile payments processor Square announced a new partnership with Starbucks that will see the company take on responsibility for processing all credit and debit card transactions at corporate-owned Starbucks in the U.S. That news came a week after  Google announced that Google Wallet has been updated to a cloud-based version that supports all credit and debit cards from Visa, MasterCard, American Express and Discover. Mobile wallet and NFC initiatives are also beginning to pick up speed in Europe — last month MasterCard and Deutsche Telekom announced a partnership to roll-out NFC payments in Europe, starting with Poland and Germany.