Rates on 30-year fixed mortgages rose slightly this week to an average of 4.23 percent, just above the lowest level in decades.
The average rate for 30-year fixed loans inched up from 4.21 percent the previous week, mortgage buyer Freddie Mac said Thursday. Earlier in the month, rates fell to 4.19 percent, the lowest average on records dating back to 1971.
The average rate on 15-year fixed loans rose to 3.66 percent. That was up from 3.64 percent a week earlier.
Rates have been falling since April. They have remained low this month because investors have been buying up Treasury bonds in anticipation of the Federal Reserve's likely move to buy Treasurys to stimulate the economy. That demand lowers Treasury yields, which mortgage rates tend to track.
Low rates haven't helped the struggling housing market, which recorded its worst summer in more than a decade. But they have led to a modest surge in refinancing.
To calculate average mortgage rates, Freddie Mac collects rates from lenders around the country on Monday through Wednesday of each week. Rates often fluctuate significantly, even within a given day.
Rates on five-year adjustable-rate mortgages averaged 3.41 percent, down from 3.45 percent a week earlier. Rates on one-year adjustable-rate mortgages remained at an average of 3.3 percent.
The rates do not include add-on fees known as points. One point is equal to 1 percent of the total loan amount.
The nationwide fee for loans in Freddie Mac's survey averaged 0.8 a point for 30-year loans. It averaged 0.7 of a point for 15-year and 1-year mortgages and 0.6 of a point for 5-year mortgages.