In its second quarter report, Fannie Mae confirmed what others have previously reported: since the first of the year, serious mortgage delinquency rates have slowly but steadily declined.

Fannie reported that delinquency levels in its portfolio fell across the board. Fannie Mae’s single-family serious delinquency rate dropped 17 basis points in July, from 5.52 to 4.82 percent. The multifamily serious delinquency rate declined 6 basis points to 0.74 percent.

In their quarterly Mortgage Metrics report released last week, the Office of the Comptroller of the Currency (OCC) and the Office of Thrift Supervision (OTS) reported that the percentage of mortgages that were seriously delinquent at 6.2 percent decreased by 5.3 percent in the second quarter.

Finally, in its September Scorecard, the Treasury Department reported that delinquency rates on prime loans have fallen from 5.6 percent a year ago to 5.2 percent in the second quarter.

Leading foreclosure databases like ForeclosureRadar and RealtyTrac also have reported a decline in serious delinquencies during 2010l.

Several factors account for the improving picture: a slowly improving economy, the decline in delinquencies resulting from subprime and alternative loans, speedier foreclosure proceedings by lenders, and private and public sector programs to modify mortgages.