WASHINGTON — Rates on 30-year mortgages rose for the first time this year after four straight weekly declines.

Mortgage company Freddie Mac reported yesterday that 30-year fixed-rate mortgages averaged 5.68 percent this week, up from 5.48 percent last week.

That had been the lowest level for 30-year mortgages in nearly four years.

Even with the increase, the 30-year mortgage remained below 6 percent for the fifth straight week.

A year ago, 30-year mortgages stood at 6.34 percent.

Analysts are hoping this low level for mortgage rates will help spur a rebound in the housing market, which suffered steep declines last year in sales of both new and existing homes.

However, the sales rebound is not expected to occur until around the middle of the year after the number of homes for sale declines to more manageable levels.

Rates on 15-year mortgages, a popular choice for refinancing, edged up to 5.17 percent, from 4.95 percent last week.

Rates on five-year adjustable-rate mortgages increased to 5.32 percent, compared with 5.13 percent last week, while rates on one-year ARMs rose to 5.05 percent, up from 4.99 percent last week.