Mortgage buyer Freddie Mac said Thursday that the average on the 30-year loan dropped to 3.62 percent. That's down from 3.66 percent last week and the lowest since long-term mortgages began in the 1950s.
The average rate on the 15-year mortgage, a popular refinancing option, slipped to 2.89 percent, below last week's previous record of 2.94 percent.
The rate on the 30-year loan has fallen to or matched record low levels in 10 of the past 11 weeks. And it's been below 4 percent since December.
Cheap mortgages have provided a lift to the long-suffering housing market. Sales of new and previously occupied homes are up from the same time last year. Home prices are rising in most markets. And homebuilders are starting more projects and spending at a faster pace.
The number of people who signed contracts to buy previously occupied homes rose in May, matching the fastest pace in two years, the National Association of Realtors reported last week. That suggests Americans are growing more confident in the market.
Low rates could also provide some help to the economy if more people refinance. When people refinance at lower rates, they pay less interest on their loans and have more money to spend. Many homeowners use the savings on renovations, furniture, appliances and other improvements, which help drive growth.
Still, the pace of home sales remains well below healthy levels. Many people are still having difficulty qualifying for home loans or can't afford larger down payments required by banks.
And the sluggish job market could deter some would-be buyers from making a purchase this year. The U.S. economy created only 69,000 jobs in May, the fewest in a year. The unemployment rate rose to 8.2 percent last month, up from 8.1 percent in April.
The government reports Friday on June employment.
Mortgage rates have been dropping because they tend to track the yield on the 10-year Treasury note. A weaker U.S. economy and uncertainty about how Europe will resolve its debt crisis have led investors to buy more Treasury securities, which are considered safe investments. As demand for Treasurys increase, the yield falls.
To calculate average rates, Freddie Mac surveys lenders across the country on Monday through Wednesday of each week.
The average does not include extra fees, known as points, which most borrowers must pay to get the lowest rates. One point equals 1 percent of the loan amount.
The average fee for 30-year loans was 0.8 point, up from 0.7 percent last week. The fee for 15-year loans also was 0.7 point, unchanged from the previous week.
The average rate on one-year adjustable rate mortgages fell to 2.68 percent, down from 2.74 percent last week. The fee for one-year adjustable rate loans rose to 0.5 point, up from 0.4 point.
The average rate on five-year adjustable rate mortgages was unchanged at 2.79 percent. The fee stayed at 0.6 point.