WASHINGTON -- Rates on 30-year mortgages edged down for the first time in six weeks as investors saw evidence that inflation is not getting out of hand.

In its weekly survey, mortgage giant Freddie Mac reported Thursday that 30-year, fixed-rate mortgages averaged 6.17 percent last week.

That was down from 6.22 percent the previous week and marked the first decline in the 30-year rate since it dropped in early March to 6.14 percent, the lowest level for this year.

Analysts attributed last week's slight decline to the latest reports on inflation, which showed few price pressures outside of energy.

"Excluding food and energy, the core inflation rate for consumer prices rose 2.5 percent year-over-year, the smallest annual growth since May 2006," said Frank Nothaft, chief economist at Freddie Mac.

Nothaft said that the low mortgage rates that have prevailed so far in 2007 may be helping to stabilize the housing market, which saw sales and construction activity fall sharply last year.

Other mortgage rates also fell last week, Freddie Mac said in its nationwide survey.

Rates on 15-year fixed-rate mortgages, a popular choice for refinancing, dipped to 5.89 percent, down from 5.90 percent the previous week.

Five-year adjustable-rate mortgages averaged 5.92 percent, compared with 5.93 percent the previous week. One-year adjustable mortgages edged down to 5.45 percent from 5.47 percent the previous week.

The mortgage rates do not include add-on fees known as points. Thirty-year and 15-year mortgages both carried a nationwide average fee of 0.5 point. Five-year adjustable-rate mortgages carried an average fee of 0.6 point while one-year ARMs carried a fee of 0.7 point.

A year ago, rates on 30-year mortgages stood at 6.53 percent while 15-year mortgages were at 6.17 percent. Five-year adjustable-rate mortgages averaged 6.16 percent.