Fixed mortgage rates declined further this week, breaking previous record lows, Freddie Mac reported Sept. 27 in its weekly Primary Mortgage Market Survey.

The 30-year fixed-rate fell 0.09 percentage points to 3.40 percent (down from 4.01 percent a year ago). The 15-year fixed-rate dropped 0.04 percent to 2.73 percent (down from 3.28 percent a year ago).

The one-year adjustable-rate mortgage dropped 0.01 percent to 2.60 percent (down from 2.83 percent a year ago). The five-year Treasury-indexed adjustable-rate decreased 0.05 percentage points to 2.71 percent (down from 3.02 percent a year ago).

"Fixed mortgage rates continued to decline this week, largely due to the Federal Reserve's purchases of mortgage securities, and should support an already improving housing market,” Frank Nothaft, Freddie Mac’s vice president and chief economist, said in a news release. “For instance, the S&P/Case-Shiller 20-city home price index rose 1.2 percent over the 12 months ending in July, reflecting the largest annual increase since August 2010. Moreover, 16 of the cities saw positive growth, led by Phoenix's 16.6 percent gain. Additionally, new home sales in July and August had the strongest two-month pace since March and April 2010,” he said.

View Freddie Mac’s weekly Primary Mortgage Market Survey.