Three of the largest wireless operators in the U.S. have signed up four of the largest credit card companies to try to kick-start mobile commerce. Isis, a joint venture among AT&T Inc. (NYSE: T), Verizon Wireless and T-Mobile US Inc. , has added Visa, MasterCard, Discover and American Express to its mobile wallet.

That means customers will be able to use those cards to make payments via Near-Field Communications (NFC)-equipped smartphones or devices when the joint venture brings the service to market, starting in Salt Lake City and Austin, Texas in early 2012. (See Isis Heads to Salt Lake City.)

Why this matters
In announcing its new partners, Isis played up the openness of its approach to mobile payments. The joint venture started out only working with Discover and Barclays Bank, with plans to build its own separate payment network, but realized it had to open its doors to big-name cards and use their networks instead. (See Carriers Can't Take the Credit.) Carrier billing won't be an option for NFC-enabled payments, as the wireless operators also recognize they're better off leaving that to familiar brand names.

"Mobile commerce is tremendously complex, because you have to bring together three industries with no connective tissue -- payment, mobile and retailers/point-of-sale," Jaymee Johnson, head of marketing at Isis, told LR Mobile in a May interview. Isis's job is to bring these parties together, he said, and the carriers' job is to put NFC phones in the hands of consumers.

According to Pyramid Research , that will start happening en masse by 2014 as upcoming smartphones start including NFC chips by default. (See Here Come the NFC Phones.)

For more
Read up on the progress of mobile commerce in North America:

• Verizon Tries Mobile Payments Solo
• NFC to Push $50B Over-the-Air by 2014
• PayPal Sues Google for Mobile Wallet
• Google Taps Sprint for Tap-to-Pay
• Operators Vie for SIM-Based NFC Control
• Sprint Stakes Its mCommerce Claim

— Sarah Reedy, Senior Reporter, Light Reading Mobile