RealtyTrac says processing delays have reduced foreclosure activity to its lowest level since the first quarter of 2008.

New data released by the tracking firm shows that foreclosure filings were reported on 681,153 properties during the first three months of this year. That represents a 15 percent decline from the previous quarter and a 27 percent drop from a year ago.

Commenting on the latest numbers, James J. Saccacio, RealtyTrac’s CEO, said despite the recent plunge in foreclosure activity, the nation’s housing market continued to languish in the first quarter.

“Weak demand, declining home prices and the lack of credit availability are weighing heavily on the market, which is still facing the dual threat of a looming shadow inventory of distressed properties and the probability that foreclosure activity will begin to increase again as lenders and servicers gradually work their way through the backlog of thousands of foreclosures that have been delayed due to improperly processed paperwork,” Saccacio said.

A total of 197,112 U.S. properties received default notices for the first time in the January to March period, a 17 percent decrease from the previous quarter and a 35 percent decrease from the first quarter of 2010.

Foreclosure auctions were scheduled for the first time on 268,995 homes. That’s down 19 percent from the previous quarter and 27 percent from the first quarter of last year.

Lenders completed foreclosure actions on 215,046 homes last quarter, a 6 percent drop from the fourth quarter of 2010 and a 17 percent decrease from the first quarter of last year. However, in states where the non-judicial foreclosure process is primarily used, RealtyTrac says bank repossessions (REOs) increased 9 percent from the previous quarter.

Illustrating the extent to which processing delays pressed foreclosure activity to artificially low levels, RealtyTrac says states where a judicial foreclosure process is used accounted for some of the biggest quarterly and annual decreases in the first quarter.

Florida foreclosure activity decreased 47 percent from the previous quarter and was down 62 percent from the first quarter of 2010, although the state still posted the nation’s eighth highest foreclosure rate with one in every 152 housing units receiving a filing in Q1.

First quarter foreclosure activity in Massachusetts fell 46 percent from the previous quarter and was down 62 percent from a year ago. The state’s foreclosure rate – one in every 549 housing units with a foreclosure filing – ranked No. 38 among the states.

New Jersey’s first quarter foreclosure rate of one in every 401 housing units with a filing ranked No. 34 among the states, thanks in part to a 43 percent decrease in foreclosure activity from the previous quarter and a 44 percent decline from the first quarter of 2010.

Connecticut’s first quarter foreclosure activity dropped 39 percent from the fourth quarter of 2010 and was down 65 percent from a year earlier. Pennsylvania posted a 35 percent decline from the previous quarter and a 29 percent drop from the same period last year.

Looking at the nationwide data for March, RealtyTrac’s report indicates that activity is already beginning to pick up some. Foreclosure filings were reported on 239,795 U.S. properties last month, up 7 percent from February. Both default notices and REOs increased in March compared to the previous month; scheduled auctions was the only stat to post a monthly decline.