WASHINGTON (AP) — U.S. long-term mortgage rates rose moderately this week, remaining at historically low levels that can lure potential purchasers in the spring homebuying season.

Mortgage buyer Freddie Mac said Thursday the average rate on the 30-year, fixed-rate mortgage increased to 4.12% from 4.08% last week. Two weeks ago, the benchmark loan rate marked its steepest weekly drop in a decade, from 4.28%.

The average rate on the 30-year loan stood at 4.42% a year ago.

The average rate this week for 15-year, fixed-rate home loans rose to 3.60% from 3.56%.

The declining trend in mortgage rates has made purchasing a home cheaper, and potential buyers have been rushing to take advantage of the lower borrowing costs.

Lower mortgage rates, slowing home price increases and a pickup in the number of available homes appear to be rejuvenating home sales after a slowdown last year.

Despite the increase in rates this week, "We expect mortgage rates to remain low ..., boosting homebuyer demand in the next few months," Freddie Mac chief economist Sam Khater said.

Freddie Mac surveys lenders across the country between Monday and Wednesday each week to compile its mortgage rate figures.

The average doesn't include extra fees, known as points, which most borrowers must pay to get the lowest rates.

The average fee on 30-year fixed-rate mortgages was unchanged this week at 0.5 point.

The average fee for the 15-year mortgage also was steady, at 0.4 point.

The average rate for five-year adjustable-rate mortgages jumped to 3.80% from 3.66% last week. The fee remained at 0.4 point.