Average fixed mortgage rates in the U.S. continued to decline in the latest week, according to mortgage-finance company Freddie Mac (FMCC), during a period marked by weakened bond yields and oil prices.

"Mortgage rates continued to fall, albeit at a slower pace," Freddie Mac Chief Economist Frank Nothaft said Thursday. Housing starts picked up in December and beat market expectations, while falling energy costs helped push producer prices and consumer prices lower, he noted.

For the week ended Thursday, the 30-year fixed-rate mortgage averaged 3.63%, compared with 3.66% a week earlier and 4.39% a year earlier. Rates on 15-year fixed-rate mortgages averaged 2.93%, compared with 2.98% the previous week and 3.44% a year earlier.

Five-year Treasury-indexed hybrid adjustable-rate mortgages, or ARMs, on average, was at 2.83%, compared with 2.9% the previous week and 3.15% a year earlier. One-year Treasury-indexed ARM rates on average were 2.37%, unchanged from the previous week but below the year-earlier average rate of 2.54%.

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

Subscribe to WSJ: http://online.wsj.com?mod=djnwires