The pace of consumer loan delinquencies stabilized in the fourth quarter of 1990 from the previous quarter, the American Bankers Association reports.

Based on a survey of 800 banks, 2.57 percent of consumer loans were at least 30 days overdue on Dec. 31, 1990, just marginally higher than 2.56 percent three months earlier, the ABA's Consumer Credit Delinquency Bulletin said.Both figures were lower than the 2.64 percent pace at the end of the fourth quarter of 1989. The quarterly rate is based on seven types of installment loans, such as mortgages.

However, bank credit card debt grew to 2.86 percent, up from 2.56 percent in the third quarter and well above 2.24 percent a year earlier, the ABA said.

"Uncertainty over the economy caused many consumers to put the brakes on new borrowing during the fourth quarter," said Robert Dugger, ABA chief economist.

Personal loans carried the highest rate of delinquency at 3.37 percent based on the total number of accounts, down from 3.49 percent in the third quarter.

Home equity delinquencies rose slightly to 0.85 percent from 0.80 percent in the third quarter.

Direct auto-loan delinquencies increased to 2.22 percent in the fourth quarter from 2.00 percent in the third quarter, while indirect loans decreased to 2.59 percent from 2.64 percent for the same period.