Average long-term U.S. mortgage rates rose this week, reaching high levels for the year.

Mortgage giant Freddie Mac says the average rate on a 30-year fixed-rate mortgage rose to 4.08 percent this week from 4.02 percent a week earlier. The rate on 15-year fixed-rate mortgages increased to 3.24 percent from 3.21 percent.

Mortgage rates have increased in recent weeks, in the midst of the spring home buying season, as the economy has shown signs of improvement.

(AP)