Data released Monday by major U.S. credit-card issuers provided the latest evidence of a slowdown in the rate of delinquent payments.

American Express Co. (AXP) and Bank of America Corp. (BAC) each announced a small decline in the level of borrowers who were at least a month behind in their payments in July compared with the month before, while Discover Financial Services Inc. (DFS) said its delinquency rate was unchanged. Capital One Financial Corp. (COF) announced a slight increase, though the level came in better than industry experts had anticipated.

Though the rates remain elevated by historical standards, the latest data should add to optimism that late payments and write-offs by credit-card issuers could peak by the end of the year. A continued 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.

The decline in delinquencies in recent months also is noteworthy because some of the seasonal factors that encouraged consumers to stay current on their bills, such as tax refund checks, already have had their positive impact. The latest numbers could indicate that consumers are finding their financial footing, though still-high jobless numbers remain a threat.

American Express said its delinquency rate fell to 4.2% in July from 4.4% in June. AmEx wrote off 9.2% of its card loans, including those packaged into bonds. For the quarter ended June 30, the company wrote off 10% of its U.S. card loans, up from 8.5% in the first quarter and 5.3% a year ago.

The company said earlier this month that better-than-expected bankruptcy trends contributed to the decline in write-offs.

Like other card issuers, AmEx is being hurt by cutbacks in spending and customers who are falling behind on their bills in the current economic slump. Unlike other card companies, AmEx both issues cards and processes transactions. It issues charge cards requiring a monthly payoff as well as credit cards on which customers can carry a balance.

An AmEx spokesman declined to comment on the company's July performance of its credit-card loans.

Discover Financial wrote off 8.43% of credit-card loans that have been packaged into bonds in July, down from 8.75% in June. The 30-day delinquency rate was nearly flat at 1.38%.

Bank of America, at 13.81%, had the highest write-off rate in July among the card issuers that released data Monday. This compares with a write-off rate of 13.86% in June.

Capital One wrote off 9.83% of its card loans last month, compared with 9.73% in June, performing better than analysts' estimates of higher losses. Its 30-day delinquencies increased to 4.83% in July from 4.77% in June, according to a regulatory filing Monday.

Officials at these companies declined to comment on the monthly reports.

The monthly report card on the performance of credit-card loans comes amid heightened scrutiny of issuers by consumer groups and legislators. Starting this week, as part of a raft of consumer protections to be implemented, issuers will face new restrictions on rate and fee increases. Issuers of plastic have responded by scaling back on credit and getting tougher on whom they lend to.

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