WASHINGTON — The number of delinquent mortgages rose while foreclosures also jumped in the third quarter, according to a report released Wednesday by federal regulators.

The Office of Comptroller of the Currency and Office of Thrift Supervision said that overall credit quality of the portfolio of first-lien mortgages remained steady during the third quarter of 2010 but a large number of seriously delinquent borrowers were moved through the foreclosure process after home retention efforts were exhausted.

In the quarterly report, the regulators found that the number of new foreclosures increased more than 382,000, or 31.2%, from the previous quarter. Foreclosures totaled 1.2 million, 10.1% more than a year earlier.

The percentage of mortgages that were 30 to 59 days delinquent increased 4.3% while the percentage of seriously delinquent (60 days or more delinquent) loans decreased by 6.4% from the previous quarter.

Servicers reported almost twice as many home retention actions as foreclosure actions. Servicers implemented 470,321 home retention efforts compared to 244,840 home forfeiture actions. But home retention actions declined 17% from the prior quarter. The OCC and OTS attributed this decline to a decline in modifications under Treasury's Home Affordable Modification Program.