Leading US retailers including Wal-Mart, Target, Best Buy and 7-Eleven have announced plans to launch their own mobile payment service that will compete with the likes of Google Wallet and Isis, the venture between the country’s three leading mobile operators.

Fourteen leading companies have formed a company called Merchant Customer Exchange, or MCX, to develop a mobile wallet that in addition to payments will provide a range of offers, promotions and retail programmes. A mobile wallet app will be available for "virtually any smartphone", says the new company.

However no launch date was announced for app. Nor the identity of the executives who will run the new company. The announcement quoted executves from Wal-Mart, Target and Best Buy. And the level of investment in the project is also unclear.

The announcement seemed to indicate the new company is also interested in serving other, smaller retailers outside the company's backers, as well as banks and credit card companies. MCX intends to "address the needs of financial institutions and merchants of all sizes" to better service mobile customers, it says.

Wal-Mart says MCX is open to other partners but they have to bring an additional capability to the service and must not layer on greater cost. Competing interests from a number of industries including retail, banking, credit card, mobile and internet are all jockeying for position in mobile payments, while being aware they also need one another.

The 14 merchants signed up to the venture so far are CVS/pharmacy, HMSHost, Lowe’s, Shell Oil Products, Publix Super Markets, Sears Holdings, Sunoco, Alon Brands, Darden Restaurants, Hy-Vee, in addition to Wal-Mart, Target, Best Buy and 7-Eleven. MCX expects to announce additional merchants in coming months.

Merchants' motivation is dissatisfaction with the existing mobile payment services on offer as well as the view they have a particular insight into shoppers'  needs, say observers.