Data firm RealtyTrac says foreclosure filings plummeted 34% in the third quarter from a year earlier. However, the CEO said the market may be a bottom, with signs activity will likely begin to grow. On average, properties stayed on the market longer in the third quarter. U.S. foreclosures spent on average 336 days in the default process. That's up from 318 days in the second quarter and the highest hold time reported in four years. In the third quarter, foreclosure filings were reported on 610,337 properties, up less than 1% from the previous quarter and a drop of 34% from the third quarter of 2010. "U.S. foreclosure activity has been mired down since October of last year, when the robo-signing controversy sparked a flurry of investigations into lender foreclosure procedures and paperwork," said James Saccacio, chief executive officer of RealtyTrac. "While foreclosure activity in September and the third quarter continued to register well below levels from a year ago, there is evidence that this temporary downward trend is about to change direction, with foreclosure activity slowly beginning to ramp back up," he said. September was the 12th straight month of excessive year-over-year declines in foreclosure filings, with 214,855 foreclosures recorded, a 6% decrease from August and a 38% decrease from September of last year. "Third-quarter foreclosure activity increased marginally from the previous quarter, breaking a trend of three consecutive quarterly decreases that started in the fourth quarter," Saccacio said. "This marginal increase in overall foreclosure activity was fueled by a 14% jump in new default notices, indicating that lenders are cautiously throwing more wood into the foreclosure fireplace after spending months spent trying to clear the chimney of sloppily filed foreclosures." Write to Kerri Panchuk.