American Express and Isis, the m-commerce joint venture between AT&T Mobility, T-Mobile USA and Verizon Wireless, have announced an agreement that will see American Express’ US Consumer, Open (small business) and Serve Cards made available through the Isis Mobile Wallet.

New York-based Isis is striving to transform how people shop and pay, and the Isis m-commerce network is being opened to all merchants, banks, payment networks and mobile carriers.

Last year, the American Express network joined Isis’ m-commerce platform and with the announcement today, American Express Cardmembers will be able to shop, ‘tap’ and pay with their smartphone, if it’s equipped with Near Field Communications (NFC) technology. The launch will begin with Salt Lake City, Utah and Austin later this year.

Serve is American Express’ new digital payments and commerce platform, and with its addition into the Isis Mobile Wallet, this will likely open the door to new customers looking to tap the latest m-commerce technology.

“The relationship with American Express underscores our commitment to ensuring a flexible and inclusive platform that offers consumers choice in mobile payments while delivering new opportunities for merchants to connect with consumers,” says Michael Abbott, CEO at Isis. “Today’s announcement is testament to the vision and commitment of American Express to make mobile commerce a real and positive experience for their customers.”

Meanwhile, you may want to read our feature on the future of online banking, where we delve into some of the latest innovations going on in the financial sphere, such as Barclays’ Pingit app, which has just passed 500,000 downloads.

This latest move by American Express only serves to stoke the fire in the race to see who becomes the dominant force in the mobile commerce space.