Standard & Poor's said U.S. bank-card charge-offs reached a record 10% in May as unemployment continued to rise, according to its U.S. Credit Card Quality Index.

As of May, the index tracked about $414.8 billion bank-card receivables and about $79.6 billion in private-label and retail card receivables backing S&P-rated asset-backed securities.

Based on unemployment forecasts of about 11% to 13% over the next year to year and a half, the ratings agency said it assumes the index will likely average losses of about the same amount.

S&P said it noted that for bank cards, principal receivables were down 5.5% from a year earlier and 1% from April. Payment amounts rose on month to 17.5% of the balance. Delinquencies of more than 30 days were 5.7%, up roughly one-third from a year ago but down 7.1% from April.

For private-label receivables, principal receivables were down 3.6% from a year earlier and up 1.2% from April. Charge-offs rose to 12.2%, up 4.6% from April, and delinquencies of more than 30 days were up from a year earlier but down from April at 6.9%.

Other firms have also noted a similar rise in bank-card charge-offs and delinquencies. Credit bureau TransUnion said last month that average bank-card debt and delinquencies rose in the first quarter as consumers struggled to repay during the housing downturn and with increased unemployment.