The two companies said Monday that Bluebird, begun during a pilot program late last year, acts like a checking account but without the fees that have increasingly frustrated shoppers. It will have no minimum balance and no monthly, annual or overdraft fees. They say the only fees that will be associated with the card will be transparent and within the user's control, such as out-of-network ATM withdrawals by consumers who don't use direct deposit.

Instead, what Bluebird will be loaded with is a number of features, including the ability to deposit a check to one's Bluebird account by simply taking a picture with a smartphone. It will also offer the same fraud protections in an event the card is stolen or lost as other standard cards.

The move comes as American Express is looking for new ways to expand its customer base beyond its traditional wealthy clientele. For Wal-Mart, the Bluebird service is the latest financial product offering to be pushed by the world's largest retailer, but it's also the most comprehensive.

Bluebird's rollout also signals how competition for pre-paid cards, once the domain of non-bank companies, is heating up.

Wal-Mart and American Express say Bluebird was improved since the pilot test, based on feedback from consumers who said they were bothered by rising fees related to checking accounts and debit services.

"We are recreating and reimagining what checking and banking services might look like in the 21st century," said Dan Schulman, group president, Enterprise Growth at American Express in an interview with The Associated Press. He said the partnership with Wal-Mart, the world's largest retailer, aims to set up a "moral equivalent of a bank branch at retail."

"Our customers tell us that they're tired of navigating a complex maze of do's and don'ts to avoid the ever growing list of fees found on checking products," Daniel Eckert, vice president of financial services for Wal-Mart U.S., said in a statement.

Deborah Weinswig, an analyst at Citi Research, said that the offering will resonate well with Wal-Mart shoppers, as only about 15 percent of the company's sales are paid for with a credit card. Bluebird "could drive increased mindshare and incremental traffic over time," Weinswig wrote in a report published Monday.

Prepaid cards are a fast-growing segment of the payments industry. While the cards are aimed mainly at people who don't have bank accounts or whose credit ratings are damaged, they also are becoming popular with consumers seeking to avoid surprise bank fees and keep from accumulating credit card balances.

But prepaid cards are typically not linked to a checking account. Monday's announcement shows how the financial service landscape is changing in light of the rising popularity of smartphones and other technological advances, and evolving needs of consumers, who want on-the-go financial services.

Wal-Mart is not new to the prepaid card segment, as it already offers prepaid cards from Green Dot Corp. During a call with reporters, Eckert said that Wal-Mart has no plans to end its relationship with Green Dot in light of its new partnership with American Express. The discounter has a contract with the Monrovia, Calif., company that expires in 2015. He says Wal-Mart is just broadening its assortment of financial services to serve more customers.

Green Dot depends on Wal-Mart for more than 60 percent of its revenue. The news sent the shares of the Monrovia, Calif.-based company plunging in Monday trading.

Bluebird cards can be used at millions of locations where American Express cards are accepted, both in the U.S. and internationally. Users can deposit funds onto the card via direct deposit, with cash at any Walmart register, or by linking a checking, savings or debit card to the account.

Another key feature: The user can set up sub-accounts for family members or others, giving them access to certain funds, instead of the entire account. So parents could set up such accounts using Bluebird for their children in college.

Madeline Aufseeser, senior analyst at research firm Aite Group, said that what makes this unique is lots of features come with the account.

"It's just a further indication that pre-paid (cards) have gone mainstream," she said.

Wal-Mart and American Express said that more features will be added to Bluebird in the first quarter of 2013. These features will include more options to deposit money and check-writing capabilities.

Bluebird will be available next week at http://www.bluebird.com/ and in more than 4,000 Walmart stores.

Shares of Bentonville, Ark.-based Wal-Mart added 13 cents to close Monday trading at $75.26. Shares of American Express, which is based in New York, gained 22 cents to end at $58.78.

Green Dot shares fell $2.618, or 20.3 percent, to close at $10.24.