In this Nov. 28, 2018, photo, a realtor sign hangs in front of a home for sale in Pittsburgh. On Thursday, Nov. 29, Freddie Mac reports on the week's average U.S. mortgage rates. (AP Photo/Keith Srakocic) WASHINGTON – U.S. long-term mortgage rates fell this week amid a steep decline in stock prices. Continued slides in the stock market and tumbling oil prices have been pushing mortgage rates lower, although home borrowing rates remain much higher than a year ago. Mortgage giant Freddie Mac says the average rate on the benchmark 30-year, fixed-rate mortgage dipped to 4.75% from 4.81% last week. The key rate stood at 3.94% a year ago. The rate on 15-year fixed-rate loans declined to 4.21% from 4.25% the previous week. The plunge in global stock markets, which have been roiled by trade tensions between the U.S. and China, deepened Thursday. The Dow Jones Industrial Average lost more than 450 points in early trading, after plummeting some 800 points on Tuesday.