Average US rate on 30-year mortgage falls to 3.98 percent; 15-year rate down to 3.17 percent

Average long-term U.S. mortgage rates fell for a second straight week, with the key 30-year rate slipping below 4 percent.

Mortgage giant Freddie Mac says the average rate on a 30-year fixed-rate mortgage declined to 3.98 percent this week from 4.04 percent a week earlier. The rate on 15-year fixed-rate mortgages eased to 3.17 percent from 3.21 percent.

As in recent weeks, mortgage rates followed the yield on the key 10-year Treasury note, which fell. Bond yields for Treasurys were pushed lower by a rise in bond prices, as investors sought safety in U.S. Treasury bonds amid steep declines in global stock markets. The yield on the 10-year note declined to 2.29 percent Wednesday from 2.33 percent a week earlier. It held steady in trading Thursday morning at 2.29 percent.