WASHINGTON – Average U.S. rates on fixed mortgages rose last week just slightly above their record lows, keeping home-buying and refinancing attractive to consumers.

Mortgage buyer Freddie Mac said Thursday the average rate on 30-year loans inched ahead to 3.34 percent, above the previous week’s rate of 3.32 percent. Two weeks ago, the rate dipped to 3.31 percent, the lowest on records dating to 1971.

The average on 15-year fixed mortgages rose to 2.67 percent from 2.64 percent a week earlier. The rate declined to 2.63 percent three weeks ago, also a record low.

Mortgage rates have been near record lows all year. That has helped fuel a modest housing recovery.

Sales of newly built and previously occupied homes are up from a year ago. Builders are more confident and are responding by starting construction on more homes.

Home prices have also increased. A report issued Tuesday by Core Logic showed that a measure of U.S. home prices rose 6.3 percent in October compared with a year earlier. That was the largest yearly gain since July 2006.

Rising prices encourage more people to sell their homes. And they lead to more buying, in part because some start to worry prices could eventually rise further.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country Monday through Wednesday of each week. The average doesn’t include extra fees, known as points, which most borrowers must pay to get the lowest rates.