WASHINGTON – Rates on 30-year mortgages dipped below the 6 percent level this week, good news for people wanting to buy a home.

Freddie Mac, in its weekly nationwide survey, said that rates on 30-year, fixed-rates mortgages fell to 5.99 percent for the week ending Aug. 5. That’s down from the average rate of 6.08 percent last week. Rates on benchmark 30-year mortgages were last below the 6 percent mark the week ending July 22.

Rates on 30-year mortgages hit a high this year of 6.34 percent the week of May 13. Since then, they have slowly drifted downward, reflecting in part a cooling in economic activity in June.

“Additional economic indicators this week confirmed that June was a weak month for the nation as a whole,” said Frank Nothaft, Freddie Mac’s chief economist. “Consequently, the upward pressure on interest rates eased, allowing mortgages to return to earlier, lower levels.”

Federal Reserve Chairman Alan Greenspan, appearing before Congress last month, called the economic slowdown in June a “soft patch.” Greenspan, however, expressed confidence the economy would pick up speed in the months ahead.

Rates on 15-year, fixed-rate mortgages, a popular option for refinancing, also declined this week to 5.40 percent, from 5.49 percent last week.

For one-year adjustable rate mortgages, rates fell to 4.08 percent this week, compared with 4.17 percent the previous week.

The nationwide averages for mortgage rates do not include add-on fees known as points. Thirty-year mortgages carried an average 0.7 point fee this week. Fifteen-year and one-year ARMs each carried an average fee of 0.6 point.

A year ago, rates on 30-year mortgages averaged 6.14 percent with 15-year mortgages at 5.44 percent and one-year ARMs at 3.68 percent.

The Mortgage Bankers Association said refinancing accounted for 35.8 percent of all home-mortgage applications filed last week.

That’s down from 36.8 percent the previous week.