Average fixed mortgage rates in the U.S. fell in the latest week, hitting new lows for 2014, according to mortgage-finance company Freddie Mac (FMCC).

Freddie Mac Chief Economist Frank Nothaft stated Thursday that mortgage rates fell along with yields on the benchmark 10-year Treasury note, which closed at the lowest level since May 2013 on Tuesday.

For the week ended Thursday, the 30-year fixed-rate mortgage averaged 3.8%, compared with 3.93% a week earlier and 4.47% a year earlier. Rates on 15-year fixed-rate mortgages averaged 3.09%, compared with 3.2% the previous week and 3.52% a year earlier.

Five-year Treasury-indexed hybrid adjustable-rate mortgages, or ARMs, on average, were at 2.95%, compared with 2.98% the previous week and 3% a year earlier. One-year Treasury-indexed ARM rates on average were 2.38%, down from 2.4% the previous week and 2.56% a year earlier.

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

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