NEW YORK (AP) -- Credit card default rates mostly fell in September, but improvements in late payments slowed for most of the major card issuers.

American Express, Discover, Chase, Bank of America and Citibank all submitted regulatory filings Friday that said September charge-offs fell to the lowest level this year.

Citi and Bank of America, which have been reporting the highest charge-off rates among the top six issuing banks all year, showed the most improvement.

Among the top six, only Capital One posted an increase in defaults, but its 8.38 percent rate remained well below its March peak for the year of 10.87 percent.

Card companies typically write off loans after they are 180 days past due, the point at which it is assumed the balances won't be able to be collected.

Banks wrote off record amounts of credit card debt in the past two years as customers failed to make payments amid high unemployment.

The overall industry charge-off rate from April to June rose to 10.66 percent of balances, according to the Federal Reserve. Charge-offs typically hovered between 3 and 4 percent in the years leading up to the recent recession.

Writedowns among the top six issuers have slowed since June, as have late payments. Earlier this week, JPMorgan Chase & Co. said in its quarterly earnings report it has lowered its estimate of future card losses. CEO Jamie Dimon said the bank expects the downward trend to continue, but added continued losses are linked to the unemployment rate. He estimated the bank's card business will "bottom out" in the third quarter of 2011.

Five of the six card issuers reported payments late by 30 days or more fell to their lowest points of the year.

American Express Co., which caters to high-income customers, had the smallest delinquency rate, at 2.5 percent of balances. Across the banks with broader customer bases, delinquency rates ranged from 3.82 percent at Chase to 5.71 percent at Bank of America.

That indicates that customers have a better handle on managing their debt than in recent months, but it is still higher than historical ranges.