Data released Tuesday by major U.S. credit-card issuers offered scant evidence of an imminent turnaround, dashing hopes that positive trends from a month earlier were gaining momentum.

The latest numbers indicate that consumers are still struggling to find their financial footing, as still-high jobless numbers remain a threat.

"Broadly speaking, the data don't give us any evidence that things are improving materially," said Sanjay Sakhrani, an analyst at Keefe, Bruyette & Woods.

This monthly report card on the performance of credit-card loans, including those packaged into bonds, comes amid heightened scrutiny around credit as losses stemming from souring card loans pile up.

Issuers of plastic, including Capital One Financial Corp. (COF), JPMorgan Chase & Co. (JPM), Bank of America Corp. (BAC), Citigroup Inc. (C), Discover Financial Services Inc. (DFS) and American Express Co. (AXP) are also coping with sweeping legislation that will bite into income. To fight the losses, card issuers are scaling back on credit and getting tougher on whom they lend to.

American Express said that U.S. borrowers at least a month behind on their card payments decreased modestly to 4.1% in August from 4.2% in July. A decline in delinquencies, a key gauge of future losses, is important for issuers because higher delinquencies force them to squirrel away capital to reserve for potential losses; ultimately, companies must write off loans if customers can't pay up.

AmEx and its peers have been hurt by cutbacks in spending and customers who are falling behind on their bills in the current economic slump. AmEx both issues cards and processes transactions. It offers charge cards requiring a monthly payoff and credit cards on which customers can carry a balance.

AmEx wrote off 9% of its card loans, including those packaged into bonds, in August. In July, the company wrote off 9.2% of its U.S. card loans.

Another card issuer, Capital One, said charge-offs - card loans deemed uncollectible - declined to 9.32% in August from 9.83% in July in its U.S. credit-card business. But cardholders at least 30 days behind payments rose to 5.09% last month from 4.83% in July. Its shares declined by 2.35%, or 90 cents Tuesday, ending the day at $37.42.

Discover said it wrote off 9.16% of credit-card loans that have been packaged into bonds in August, up from 8.43% in July. Delinquencies also edged up to 5.35% last month compared with 5.28% in July.

Bank of America, at 14.54%, had the highest write-off rate in August among the card issuers that released data Tuesday. It wrote off 13.81% of card loans in July - also the highest rate at the time among its peers.

Citigroup, at 12.14%, had the second-highest write-off rate in August, up from 10.03% in July. The company's shares declined by 8.85%, or 40 cents Tuesday, ending the day at $4.12. Officials at these companies were either unavailable for comment or declined to comment.

Chase, a unit of JPMorgan Chase, said its annualized credit-card charge-off rate rose to 8.73% in August, up from 7.92% in July.

"We continue to be concerned about the loss environment and we believe we are taking the appropriate steps to continue mitigating our risk," said Paul Hartwick, a Chase spokesman.

- By Aparajita Saha-Bubna, Dow Jones Newswires; 617-654-6729; aparajita.saha-bubna@dowjones.com

(Tess Stynes in New York contributed to this article.)