WASHINGTON — Rates on 30-year mortgages sank this week to a one-month low, while rates on most other mortgages also fell, good news to prospective home buyers.

Freddie Mac, the mortgage company, reported yesterday that 30-year fixed-rate mortgages averaged 6.63 percent. That was down from last week's 6.67 percent rate and was the lowest since early June, when rates stood at 6.53 percent.

The moderation is welcome for people in the market to buy a home. In mid-June, rates on 30-year mortgages climbed to 6.74 percent, an 11-month high.

Rates on many mortgages have ebbed in recent weeks as investors' fears about inflation have eased.

"Long-term mortgage rates continued to move lower for a third consecutive week, in part reflecting a moderation in core inflation," which excludes food and energy prices, said Frank Nothaft, Freddie Mac's chief economist.

The Federal Reserve in deciding to hold a key interest rate steady last week noted that some readings on core inflation have improved. The Fed's key rate has been at 5.25 percent for a year, offering borrowers a period of steadiness.

Some other mortgage rates tracked by Freddie Mac also showed declines this week.

Rates on 15-year fixed-rate mortgages, a popular choice for refinancing, fell to 6.30 percent from 6.34 percent last week. And, rates on five-year adjustable-rate mortgages averaged 6.29 percent, down slightly from last week's 6.30 percent.

However, rates on one-year adjustable-rate mortgages rose to 5.71 percent this week, compared with 5.65 percent last week.

The mortgage rates do not include add-on fees known as points. All mortgage types each carried a nationwide average fee of 0.4 point last week.

A year ago, rates on 30-year mortgages stood at 6.79 percent, 15-year mortgages were at 6.44 percent, five-year adjustable-rate mortgages averaged 6.39 percent and one-year ARMs were at 5.82 percent.