Rates on 30-year mortgages fell for a second straight week to the lowest level since the beginning of the year.

Mortgage giant Freddie Mac (FRE) reported Thursday that 30-year, fixed-rate mortgages averaged 6.18 percent this week, down from 6.22 percent last week.

The decline pushed rates down to the lowest point since the 30-year mortgage was at the same 6.18 percent the week of Jan. 4.

Analysts said this week's drop reflected weak economic data and the huge 416-point plunge in the stock market on Tuesday, which pushed investors to seek the safety of bonds.

Frank Nothaft, chief economist for Freddie Mac, pointed to "new economic information suggesting a slower economy and lower inflation."

The government on Wednesday revised its estimate for overall economic growth to an annual rate of just 2.2 percent in the fourth quarter of 2006, sharply lower than an initial estimate of 3.5 percent growth during that period.

The Freddie Mac survey showed that other types of mortgage rates edged down this week as well.

Rates on 15-year, fixed-rate mortgages, a popular choice for refinancing, fell to 5.92 percent, down from 5.97 percent last week.

Five-year adjustable rate mortgages edged down to 5.93 percent, compared with 5.96 percent last week.

One-year ARMs were unchanged at 5.49 percent, the same as last week.

The mortgage rates do not include add-on fees known as points. Thirty-year mortgages carried a nationwide average fee of 0.4 point while 15-year mortgages had an average fee of 0.5 point.

Five-year adjustable rate mortgages and one-year ARMs both carried a fee of 0.6 point.

A year ago, rates on 30-year mortgages stood at 6.24 percent while 15-year mortgages were at 5.89 percent, five-year adjustable rate mortgages averaged 5.97 percent and one-year ARMs were at 5.34 percent.