WASHINGTON (AP) — Long-term U.S. mortgage rates edged higher this week, remaining near historically low levels as a continued enticement to prospective homebuyers.

Mortgage giant Freddie Mac said Thursday the average for the benchmark 30-year fixed-rate mortgage rose to 3.45 percent from 3.42 percent last week. The average rate is down sharply from 4.04 percent a year ago.

The 15-year fixed mortgage rate increased to 2.75 percent from 2.72 percent last week.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country at the beginning of 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 remained at 0.5 point this week. The fee for a 15-year loan also was unchanged from last week at 0.5 point.

Rates on adjustable five-year mortgages averaged 2.78 percent, up from 2.76 percent last week. The fee rose to 0.5 point from 0.4 point.