Isis and Google Wallet may have some new competition on their hands. Walmart, Target, and about two dozen other retailers are joining forces in the development of a mobile payment system to rival the two. The retailers are unhappy with the way these companies are handling business and want to get in on the fast paced market on their own.

In a statement to the Wall Street Journal, Target said: “We are exploring potential solutions that would help us to deliver the fastest, most secure mobile-payment experience possible for our customers.”

No details have been released about when it will launch, but they will have to move quickly to compete with Google Wallet. The company has grown by leaps and bounds since it launched last September on the Sprint Nexus S. Since then they claim support from 22 of the largest U.S. Retail chains, allowing users access to over 300,000 MasterCard PayPass-enabled terminals. Just this week they have announced ten new phones that will support the app.

Isis, the mobile payment system offered by Verizon, AT&T and T-Mobile, has already announced plans to launch its service this summer. Isis, like Google Wallet, will enable consumers to conduct point-of-sale transactions and use loyalty cards via their mobile device carriers.

More and more retailers are looking for the inside track in an industry that is expected to double or triple in next few years, potentially reaching $670 billion transactions by 2015.