WASHINGTON (AP) _ Rates for 30-year and 15-year mortgages edged down this week but adjustable-rate mortgages ticked up.

The average interest rate on 30-year fixed-rate mortgages slipped to 7.73 percent for the week ending Nov. 17, down from 7.79 percent reached the previous week, according to a survey released Thursday by Freddie Mac, the mortgage company. A year ago, the rate on 30-year mortgages stood at 7.69 percent.

In mid-May, rates on 30-year mortgages hit a five-year high of 8.64 percent.

Fifteen-year mortgages, a popular option for refinancing, fell to an average 7.41 percent this week from 7.44 percent last week. A year ago, 15-year mortgages averaged 7.31 percent

On one-year adjustable-rate mortgages, lenders were asking an average initial rate of 7.25 percent, up from 7.23 percent the week before. For the same period last year, one-year ARMS averaged 6.35 percent.

The rates do not include add-on fees known as points, which averaged 1 percent of the loan amount for all three types of mortgages.