WASHINGTON - Average long-term U.S. mortgage rates fell this week amid continued turbulence in global stock markets.

It was the second straight weekly decline for the rate on the key 30-year loan. Mortgage buyer Freddie Mac says the average rate on a 30-year fixed-rate mortgage dipped to 3.92 percent from 3.97 percent a week earlier. That rate has increased from its 3.66 percent average a year ago but remains well below its historic average of 6 percent.

The average rate on 15-year fixed-rate mortgages eased to 3.19 percent from 3.26 percent.

The tumult in stock markets around the world that started off the year, triggered by economic stability in China, continued in the latest week. That has pushed up prices of U.S. government bonds, depressing their yields, which mortgage rates track.