Mortgage rates fell to new record lows during the week ending Nov. 21, Freddie Mac said in its latest primary mortgage market survey.   

Fixed rates remained well below 4% even as homebuilder confidence rose for the sixth consecutive month and existing home sales edged up 2.1% in October, the GSE report said.

The 30-year, fixed-rate mortgage averaged 3.31%, down from 3.34% a week earlier and a decline from 3.98% a year ago.  

The 15-year, FRM averaged 2.63%, down from 2.65% a week earlier and 3.30% from last year.

The 5-year, Treasury-indexed hybrid ARM remained unchanged at 2.74%, but is down from 2.91% last year.

In addition, the 1-year Treasury-indexed ARM hovered at 2.56% this past week, up from 2.55% a week earlier and 2.79% last year.

Freddie Mac executives continue to see the low rates as a potential stimulus for the housing market.

"Fixed mortgage rates continued to ease somewhat this week to record lows and should help the ongoing housing recovery," said Frank Nothaft, vice president and chief economist of Freddie Mac.

The Bankrate survey shows interest rates falling even lower, with the 30-year, FRM holding at 3.53%, down from 3.54% a week earlier.

The 15-year, FRM in the Bankrate survey hit 2.86%, down from 2.87% last week, and the 5/1 ARM hovered at 2.70%, down from 2.72% a week earlier.