WASHINGTON — Rates on 30-year mortgages fell for the second straight week, declining to the lowest level in more than a month.

Freddie Mac, the mortgage company, reported yesterday that 30-year, fixed-rate mortgages dropped to 6.40 percent this week, down from 6.47 percent last week. The new rate was the lowest since the week of July 17.

The 30-year mortgage has been above 6 percent since late May, reflecting the view of financial markets that rising inflation pressures will keep the Federal Reserve from cutting interest rates further even though the economy is still mired in a period of significant weakness.

The Freddie Mac survey showed that other mortgage rates were mixed this week.

Rates on 15-year, fixed-rate mortgages, a popular choice for refinancing, fell to 5.93 percent, down from 6 percent last week.

Rates on five-year, adjustable-rate mortgages averaged 6.03 percent this week, up slightly from 5.99 percent last week.