LOS ANGELES (AP) - More Americans fell behind on their credit card payments in the third quarter, when many consumers traditionally hit stores for back-to-school supplies. Credit reporting agency TransUnion said Wednesday that the rate of credit card payments at least 90 days overdue was 1.36 percent in the July-September quarter. That's up from 1.27 percent in the previous three-month period, but down from 1.50 percent in the third quarter last year. The latest card delinquency rate remains the second-lowest on TransUnion's records, which go back to 2007. Card balances have been dropping over the past year and remain near historically low levels. Still, TransUnion expects the card delinquency rate to rise slightly in the fourth quarter as many holiday season shoppers put off credit card payments until early next year.