Rates on 30-year mortgages declined for a third consecutive week as bond investors worried that Hurricane Katrina and soaring energy prices will slow the economy.

Mortgage giant Freddie Mac reported Thursday that rates on 30-year, fixed-rate mortgages fell to a nationwide average of 5.71 percent this week, down from last week’s 5.77 percent. Rates are now at their lowest point since mid-July and significantly below the four-month high of 5.89 percent, which hit during the week of Aug. 11.

Analysts said the continued low mortgage rates were helping to keep housing markets red hot and predicted that rates could go still lower, given an expected economic slowdown from the hurricane and rising energy prices.