ORLANDO, Florida (Reuters) - AT&T Inc. (NYSE:T - news) said on Tuesday it has taken a step toward the long-promised notion of phones replacing credit cards, checks and cash by signing agreements with Wachovia Corp. (NYSE:WB - news) and several other banks.

The agreements will allow customers of its Cingular Wireless arm, which is being rebranded as AT&T, and participating banks to manage their accounts and pay bills electronically by using an application on their cell phones. While the use of mobile phones for transactions is in its nascent stages in the United States, such services are already available in parts of Europe and Asia.In Japan, people commonly shop with their mobile phones by just waving their handset instead of swiping credit cards.

AT&T, having tested mobile banking last year, has said it will not charge extra for the service but expects it to attract more users to its wireless Internet service and potentially help it add new users and keep existing ones.Along with Wachovia, U.S. banks such as BancorpSouth Inc. (NYSE: BXS - news), Regions Financial Corp. (NYSE:RF - news) and SunTrust Banks Inc. (NYSE:STI - news) are offering mobile banking to AT&T customers. The move is part of an effort by wireless companies around to world to boost their revenue and customer loyalty by convincing subscribers to use phones for everything from Web browsing and text messaging to playing music and video.

AT&T said customers can download software from privately held Firethorn Holdings LLC onto their phones. AT&T plans to include the software in new handsets in the second half of this year and is planning a multimillion-dollar ad campaign.Firethorn is also acting as an intermediary between AT&T and the banks.

AT&T said most BancorpSouth customers who tried mobile banking said they would use it to check their balance, and about three quarters said it would help them make better spending decisions. Wachovia operates in 21 U.S. states, while Regions operates in 16 states in the Midwest and South, including Texas. SunTrust provides banking in Southeast and Mid-Atlantic states and BancorpSouth operates in eight U.S. states.

AT&T Chief Operating Officer Randall Stephenson talked about the mobile banking service in a keynote speech at the CTIA wireless technology conference on Tuesday. He also commented on combining wireless and fixed-line services. "I’m confident that in the not too distant future the concepts of having different handsets for different networks ….. will be seen as quaint," Stephenson said. For example, cell phone video conference services that AT&T plans to launch in 50 markets this summer could eventually work in conjunction with video conferencing on television screens and desktop computers."You should fully expect in a very short period that the other two screens will be brought into this," said Stephenson. He saw mobile video representing as dramatic a change as the replacement of black-and-white televisions with color. To illustrate the growing ubiquity of mobile phones around the world, Stephenson said that while four babies are born every second in China, about 25 people are signing up for wireless services in the country.

Online companies continue to push mobile services and products even while demand has been light. The expectation is that people will want to shop online and surf the Web from increasingly sophisticated cell phones and handhelds. PayPal launched a service last year that lets people transfer money via text messages.