WASHINGTON (AP) — Average long-term U.S. mortgage rates fell this week, retreating from high levels for the year amid economic turbulence overseas. The lower rates brought an incentive for prospective purchasers toward the end of the spring home buying season.

Mortgage giant Freddie Mac says the average rate on a 30-year fixed-rate mortgage declined to 4.04 percent this week from 4.08 percent a week earlier. The rate on 15-year fixed-rate mortgages eased to 3.20 percent from 3.24 percent.

Markets around the world have been nervously watching tumult and a nearly month-long slide in China's stock markets, and Greece's economic crisis as it tries to negotiate a rescue from its European partners. That has pushed investors to seek safety in U.S. Treasury bonds, pushing interest rates lower.