WASHINGTON (AP) — Rates on 30-year and 15-year mortgages moved down this week, good news for people interested in buying a home.

For the week ending Dec. 12, the average rate on 30-year, fixed-rate mortgages fell to 5.88 percent, down from 6.02 percent the previous week, Freddie Mac, the mortgage giant, reported Thursday in its weekly nationwide survey of mortgage rates.

Rates on 30-year mortgages slid to 5.21 percent, the lowest level in more than four decades, in the middle of June. Since then, rates on these benchmark mortgages have bounced up and down.

For 15-year fixed-rate mortgages, a popular option for refinancing, the average rate dropped to 5.24 percent, down sharply from 5.36 percent last week.

Rates for one-year adjustable mortgages, however, averaged 3.77 percent, unchanged for the third straight week.

A year ago, rates on 30-year mortgages averaged 6.04 percent, 15-year mortgages were 5.46 percent and one-year adjustable mortgages stood at 4.18 percent.

The nationwide averages for mortgage rates do not include add-on fees known as points. Thirty-year loans carried an average fee of 0.7 point this week. Fifteen-year and one-year adjustable rate mortgages each carried an average fee of 0.6 point.