Washington ? Rates on 30-year and 15-year mortgages dropped for a third straight week to levels that homebuyers haven’t been able to take advantage of since the spring.

Freddie Mac said Thursday, in its weekly nationwide survey, that rates on benchmark 30-year, fixed-rate mortgages fell to 6.01 percent this week, down from 6.21 percent last week. It was the lowest level since mid-April.

Thirty-year rates hit a low this year of 5.38 percent the week ending March 18.

“This is good news for those who are still house-hunting, as lower rates mean more affordable housing,” said Frank Nothaft, Freddie Mac’s chief economist.

Rates for 15-year, fixed-rate mortgages dropped to 5.42 percent this week, down from 5.62 percent last week. It was the lowest level since the end of April.

Rates on one-year adjustable rate mortgages also were down, falling to 4.05 percent from 4.19 percent the previous week.

A year ago, rates on 30-year mortgages averaged 5.4 percent, with 15-year mortgages at 4.75 percent and one-year ARMs stood at 3.49 percent.