The percentage of mortgages classified as seriously delinquent within the portfolios of large banks and thrifts fell in all four quarters of 2010, the Office of the Comptroller of Currency and the Office of Thrift Supervision said Thursday. The percentage of seriously delinquent mortgages at Dec. 31 dropped to a level not seen since the second quarter of 2009. The report defines seriously delinquent mortgages as those 60 or more days delinquent or delinquent loans to bankrupt borrowers. The federal agencies said 87.6% of the nearly 33 million loans surveyed were listed as current and performing at the end of the fourth quarter. During the quarter, foreclosure activity declined as mortgage servicers slowed the default process to deal with regulatory issues surrounding foreclosure processes. “Completed foreclosures decreased by nearly 50% to 95,067,” the OCC and OTS report said. “Newly initiated foreclosures decreased by almost 8% to 352,318. Because new foreclosures outpaced completed foreclosures, the inventory of foreclosures in process increased by more than 7% to 1,290,253; that represented 3.9% of all serviced loans at the end of the fourth quarter.” Despite the foreclosure slowdown, the OCC and OTS  expect foreclosure activity to increase in 2011 as moratoriums thaw, allowing a larger inventory of distressed loans to enter the foreclosure process. In the fourth quarter, servicers launched three times as many loss mitigation procedures when compared to home forfeiture actions, the agencies said. “Servicers implemented 473,415 home retention actions (loan modifications, trial period plans, and shorter term payment plans), compared with 146,132 completed home forfeiture actions (completed foreclosures, short sales, and deed-in-lieu-of-foreclosure actions),” the report said. Write to Kerri Panchuk.