WASHINGTON — Rates on 30-year mortgages fell for a sixth straight week, dropping to the lowest level in three months, according to a weekly survey released yesterday.

Mortgage giant Freddie Mac said rates on 30-year, fixed-rate mortgages dipped to 6.10 percent this week, down from 6.15 percent last week.

Rates have been falling since mid-December when rates on the 30-year mortgage were at 6.32 percent. The rate is now the lowest since the week of Oct. 20.

"Over the last six weeks, long-term mortgage rates have dropped nearly a quarter of a percent in the face of little or no inflationary pressures," said Frank Nothaft, chief economist at Freddie Mac.

Even with the declines, rates are still higher than they were a year ago, reflecting a campaign by the Federal Reserve to boost interest rates as a way of slowing the economy enough to keep inflation under control.

Many economists believe those higher rates will cool the booming housing market that has seen construction of single-family homes and sales of both new and existing homes soar to record levels.

Separately, the Commerce Department said yesterday construction of new homes and apartments dropped a sharp 8.9 percent in December, which was seen as strong evidence that the housing market is starting to cool.

Rates on 15-year, fixed-rate mortgages averaged 5.67 percent this week, down from 5.71 percent last week.

One-year adjustable rate mortgages edged up slightly to 5.18 percent, compared to 5.15 percent last week. Rates on five-year hybrid adjustable rate mortgages dipped to 5.75 percent, down from 5.76 percent last week.