U.S. mortgage foreclosure filings fell for a second straight month in September, but remained near a record high, amid ongoing and sweeping efforts to keep borrowers in their homes, a report released on Thursday showed.

Foreclosure filings -- including mortgage default notices, house auctions and home repossessions by banks -- were reported on 343,638 properties in September, down 4 percent from August, but up 29 percent from the year-earlier month, real estate data firm RealtyTrac said.

September's decrease was much bigger than August's month-on-month drop of less than 1 percent from July's all-time high, indicating foreclosure prevention efforts may be gaining traction.

Despite the monthly decrease, September's total was still the third highest monthly total since the RealtyTrac report began in January 2005, behind only July and August of this year, Irvine, California-based RealtyTrac said.

Foreclosures that were delayed by various state and federal moratorium that mostly ended in March have been pushing through the system and analysts say the Obama administration's housing rescue plan has been slow to take hold.

REOs, or real estate-owned properties, rose to 87,821 in September from 76,134 the previous month, RealtyTrac said. Activity in the third quarter reached a record level.

Foreclosure filings were reported on 937,840 properties between July and September, a 5 percent increase from the previous quarter and an increase of nearly 23 percent from the same period a year earlier, the company said in its U.S. Foreclosure Market Report.

One in every 136 U.S. housing units received a foreclosure filing during the third quarter -- the highest quarterly foreclosure rate since RealtyTrac began issuing its report in the first quarter of 2005.

Bank repossessions, or REOs, jumped 21 percent from the second quarter to the third quarter, corresponding to jumps in defaults and scheduled auctions in the previous two quarters, James J. Saccacio, chief executive officer of RealtyTrac, said in a statement.

REO activity increased from the previous quarter in all but two states and the District of Columbia, indicating that lenders may be starting to work through some of the pent-up foreclosure inventory caused by legislative delays, loan modification efforts and high volumes of distressed properties, he said.

Some people believe current housing-rescue efforts fail to address current drivers of foreclosures, namely borrowers with good credit who have lost their jobs and cannot afford to make any mortgage payments.

There are also borrowers who have complex mortgages that cannot be easily modified without writing down the loan balance, which is something mortgage companies have been hesitant to initiate.

Nevada, once one of the hottest U.S. real estate markets, continued to document the nation's highest state foreclosure rate in the third quarter, with one in 23 housing units receiving a foreclosure filing -- nearly six times the national average.

Foreclosure filings were reported on 47,925 Nevada properties during the quarter, an increase of nearly 10 percent from the previous quarter and an increase of nearly 59 percent from the third quarter of 2008.

Arizona posted the nation's second highest state foreclosure rate in the third quarter, with one in every 53 housing units receiving a foreclosure filing. Foreclosure filings were reported on 50,342 Arizona properties during the quarter, an increase of about 5 percent from the previous quarter and an increase of nearly 25 percent from the third quarter of 2008.

California, the most populous U.S. state, posted the nation's third highest state foreclosure rate, also with one in every 53 housing units receiving a foreclosure filing during the quarter.

Foreclosure filings were reported on 250,054 California properties during the quarter, a decrease of nearly 2 percent from the previous quarter, but an increase of nearly 19 percent from the third quarter of 2008.

Other states with foreclosure rates ranking among the top 10 in the third quarter were Florida, Idaho, Utah, Georgia, Michigan, Colorado and Illinois.

(Editing by Andrew Hay)