Foreclosures started by lenders in Massachusetts during September declined from August by 23 percent and dropped 6.7 percent from a year earlier, according to a new report by the Boston-based research firm the Warren Group.

Lenders filed 2,358 petitions to foreclose in September, the first step in the foreclosure process. The Warren Group reports that these petitions have exceeded 2,000 since February with 20,964 foreclosure petitions filed so far this year statewide, but that’s a 3.1 percent decrease from the same period in 2009.

“We saw more moderate activity in September,” said the Warren Group’s CEO, Timothy M. Warren Jr. “Earlier

this year, petitions were rising at a dramatic clip, including months when the increases were 80 percent to 121 percent.”

Warren added that Bank of America’s decision to halt foreclosures in Massachusetts will impact the numbers, but it won’t be clear by how much until the October statistics are tabulated, pending a review of the bank’s paperwork and procedures.

“From what we can see at the present time, Bank of America is involved in about 2,000 pending foreclosure cases in the Bay State,” Warren said.

In addition, the number of completed foreclosures increased for the ninth straight month in Massachusetts.

Recorded foreclosure deeds jumped 26.6 percent in September to 890 from a year earlier, while foreclosure deeds dropped from August’s 1,207 foreclosures.

This is the first month since February when foreclosure deeds fell below 1,000. Year-to-date foreclosure deeds rose more than 58 percent to 10,777, up from 6,796 a year earlier.

“Although foreclosure deeds increased from a year ago, this is the lowest level we’ve seen so far this year,” Warren said. “If fewer people are losing their homes to foreclosure, it bodes well for the housing market as a whole.”