Fixed mortgage rates remained unchanged from last week, according to the weekly market survey from Freddie Mac.

The 30-year fixed-rate mortgage averaged 3.87% for the week ending Thursday, the third straight week at that level, an all-time low. It's also the 11th consecutive week under 4%, and down from a 5% average for the 30-year FRM a year ago.

The 15-year FRM stayed at 3.16%, matching last week's average and down from 4.27% from 2011.

Frank Nothaft, chief economist for Freddie Mac, said the unaltered rates come amid mixed economic signals, including a decline in consumer sentiment and a four-year high in homebuilder confidence.

The 5-year Treasury-indexed hybrid adjustable-rate mortgage dipped slightly to 2.82% from 2.83% last week, and declined from 3.87% last year. The 1-year ARM rose to 2.84% from 2.78%, and fell from 3.39% a year earlier.

Bankrate reported a decline in interest rates this week, with the 30-year FRM down to 4.1% from 4.14% last week, and the 15-year FRM down to 3.35% from 3.36%. The 5/1 ARM fell to 3.03% from 3.05%.