WASHINGTON (AP) — 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 said Thursday 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 fall in mortgage rates "is a welcome relief to prospective homebuyers who have recently experienced rising rates and rising home prices," Freddie Mac chief economist Sam Khater said.

The plunge in global stock markets, which have been roiled by trade tensions between the U.S. and China, initially deepened Thursday. The Dow Jones Industrial Average lost as much as 784 points in volatile trading, after plummeting some 800 points on Tuesday. But the market staged a recovery later in the day, and the Dow average finished only 79.40 points lower. U.S. markets were closed Wednesday because of the national day of mourning for President George H.W. Bush.

Thursday's broad decline came as news of the arrest of a senior Chinese technology executive overshadowed some positive comments on trade from Beijing, threatening to worsen U.S.-China trade tensions.

With stocks sliding, traders continued to channel money into bonds — a signal that they see weakness in the economy ahead. The yield on the key 10-year Treasury note, which tends to influence mortgage rates, dropped to 2.86% Thursday morning from 2.92% on Tuesday as bond prices rose.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country between Monday and Wednesday each week.

The average doesn't include extra fees, known as points, which most borrowers must pay to get the lowest rates.

The average fee on 30-year fixed-rate mortgages was unchanged this week at 0.5 point. The fee on 15-year mortgages held steady at 0.4 point.

The average rate for five-year adjustable-rate mortgages fell to 4.07% from 4.12% last week. The fee remained at 0.3 point.