15-year mortgages at record low 2.56% avg.

WASHINGTON (AP) — The average rate on a 15-year fixed mortgage fell to a new low last week, and the rate on the 30-year fixed loan declined.

Cheaper mortgage rates have encouraged home-buying and refinancing.

Mortgage buyer Freddie Mac says the average rate for a 15-year fixed mortgage slipped to 2.56%. That's the lowest on records dating to 1991. It fell from 2.61% last week, the previous record.

The rate on 30-year loans declined to 3.35% from 3.40% last week. That's near the average of 3.31%in November, lowest rate on records dating back to 1971.

Low mortgage rates have helped sustain a housing recovery that began last year. Home prices and sales are rising, and construction is up.