The number of completed foreclosures last year in Massachusetts dropped by nearly 13 percent to 7,424, down from 8,531 the previous year, the Warren Group said in a press release.

But the number of foreclosure petitions started in the Bay State increased by more than 35 percent to 17,152. In 2011, there was a big drop in petitions as lenders slowed the process as their procedures came under scrutiny, said the Warren group, a Boston firm that tracks real estate activity..

Foreclosure deeds represent completed foreclosures. The first step in the foreclosure process is a foreclosure petition.

There were 265 foreclosure deeds recorded in Massachusetts during December, a 65 percent decrease from the number recorded in the same month a year ago.

In December, 835 foreclosure petitions were started in Massachusetts, down 17 percent on a year-to-year basis.

“Foreclosure activity nationwide is declining, and Massachusetts is following the same path,” Warren Group chief executive Timothy M. Warren Jr. said in a statement. “Deeds were down for the year, petitions declined for the past two months, and I think that will continue.”

Timothy Warren added: “Foreclosures have been trending down for several years now. A robust real estate market will ensure that this trend continues in 2013.”