Mortgage buyer Freddie Mac said Thursday that the average rate on the 30-year loan fell to 4.51 percent. That's down from 4.58 percent last week, the highest since July 2011.
The average on the 15-year fixed mortgage dipped to 3.54 percent from 3.60 percent, also the highest since July 2011.
Rates have risen more than a full percentage point since May when Chairman Ben Bernanke first signaled that the Federal Reserve might reduce its bond purchases later this year. The purchases have helped keep long-term interest rates low.
Mortgage rates remain low by historical standards. But the sudden spike in rates could slow the housing recovery's momentum.
U.S. sales of newly built homes dropped 13.4 percent in July to a seasonally adjusted annual rate of 394,000, the government said last week. That's the lowest level in nine months.
Also in July, fewer Americans signed contracts to buy homes for the second straight month, according to the National Association of Realtors. Still, the decline has been modest and the level of pending homes sales remains close to a 6 ½ -year high reached in May.
Mortgage rates have been rising because they tend to follow the yield on the 10-year Treasury note. The yield also has surged on speculation that the Fed's stimulus will slow. But the rate on the 10-year note declined this week to 2.78 percent from 2.90 percent last week.
To calculate average mortgage rates, Freddie Mac surveys lenders across the country on Monday through Wednesday each week. The average doesn't 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 a 30-year mortgage declined to 0.7 point from 0.8 point. The fee for a 15-year loan was unchanged at 0.7 point.
The average rate on a one-year adjustable-rate mortgage fell to 2.64 percent from 2.67 percent. The fee slipped to 0.4 point from 0.5 point.
The average rate on a five-year adjustable mortgage rose to 3.24 percent from 3.21 percent. The fee held at 0.5 point.