Mortgage delinquency rates decreased in the fourth quarter, but at a slower pace than previous quarters, according to a report released Wednesday by TransUnion. The final quarter of 2010 is setting the pace for this year, and the credit bureau expects only modest fluctuations in delinquency rates in 2011. The ratio of borrowers 60 days of more delinquent on their mortgages dropped to 6.41% in the fourth quarter from 6.44% the quarter before. Compared to the same period in 2009, mortgages delinquencies are down about 7%, TransUnion reported. In the third quarter, the national rate tumbled 3.5%. "The current deceleration in falling mortgage delinquency rates is indeed concerning," said Tim Martin, vice president of the U.S. Housing Market sector of TransUnion's financial business unit. While economic indicators such as gross domestic product and consumer confidence are generally positive, home prices are still dropping. "What we hoped was a temporary third quarter price adjustment due to the ending of the home buyer tax credit appears now to be more systemic," according to Martin. Thirty-three states witnessed increases in delinquency rates between the third and fourth quarters. North Dakota, although it has the lowest delinquency rate across the nation, saw a 13.16% jump for the period, while Vermont's rate increased 10.87% and Washington D.C.'s increased 7.4%. Nevada and Florida posted the highest delinquency rates for the three months ended Dec. 31 at 14.76% and 14.5%, respectively. North Dakota and South Dakota continued to experience the lowest delinquency rates at 1.72% and 2.273%, respectively. Alaska had the third lowest delinquency rate at 2.73%. Although the majority of states saw delinquency rates rise in the fourth quarter, the amount of later stage delinquencies (90 days or 120-plus days) suggest a possible deceleration in foreclosure rates, TransUnion said. The firm expects the national delinquency rate will likely remain flat or edge up slightly in 2011, "but begin to drift lower by year end." In December, the firm predicted double-digit decreases in the delinquency rate nationwide. The average mortgage debt per borrower on a national basis also fell in the fourth quarter, down 0.59% to $189,046. This figure is down 2.4% from the same period a year earlier when mortgage debt averaged $193,690 per borrower. Write to Christine Ricciardi. Follow her on Twitter @HWnewbieCR.