Average fixed-mortgage rates in the U.S. edged down in the latest week, with the 30-year-fixed rate moving to just below 4%, according to mortgage-finance company Freddie Mac (FMCC).

Freddie Mac Chief Economist Frank Nothaft stated Thursday that fixed mortgage rates were down slightly amid a report that housing starts declined 2.8% in October, below the upwardly revised September rate. Data also showed building permits increased 4.8% last month after a 2.8% boost during September.

For the week ended Thursday, the 30-year fixed-rate mortgage averaged 3.99%, compared with 4.01% a week earlier and 4.22% a year earlier. Rates on 15-year fixed-rate mortgages averaged 3.17%, compared with 3.2% the previous week and 3.27% a year earlier.

Five-year Treasury-indexed hybrid adjustable-rate mortgages, or ARMs, on average, was at 3.01%, compared with 3.02% the previous week and 2.95% a year earlier. One-year Treasury-indexed ARM rates on average were 2.44%, from 2.43% the previous week and 2.61% a year earlier.

Write to Tess Stynes at tess.stynes@wsj.com

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