WASHINGTON | Rates on 30-year mortgages fell to a record level for a fourth straight week, dropping to the lowest mark since Freddie Mac started tracking the data nearly 28 years ago.

Rates have been falling since late November, when the Federal Reserve announced a plan to spend up to $500 billion to buy-up mortgage-backed securities in efforts to buttress the distressed U.S. housing market.

Freddie Mac reported Thursday that average rates on 30-year fixed mortgages dropped to 5.01 percent this week, down from the previous record of 5.1 percent set last week. It was the 10th straight weekly drop, and nearly a full point below the rate of 5.87 percent at the same time last year.

Rates at are their lowest since the company started its survey in April 1971. They have declined nearly 1.5 percentage points since October, Freddie Mac said.

For a borrower taking out a $200,000 loan, that means a savings of more than $184 in monthly payments, according to Frank Nothaft, the mortgage finance company's chief economist.

The falling rates have led to an increase in mortgage applications until last week. The Mortgage Bankers Association reported Wednesday that its weekly mortgage application index fell 8.2 percent for the week ended Jan. 2 compared to the previous week.

While the lower mortgage rates help mortgage holders with good credit and plenty of home equity who want to refinance, they do little to help those in foreclosure.

In scenic Clearwater Beach, Fla., Valerie Saunders has seen a "dramatic upswing" in interest from people who want to refinance at her mortgage company, R.E. Financial Services Inc. Saunders said she closed two transactions for 30-year-fixed rate mortgages Wednesday, with a rate of 5 percent on one and 4.875 on the other.

"People should be jumping on it and taking advantage of these rates," Saunders said. "It's only going to have a positive effect."

The average rate on a 15-year fixed-rate mortgage dropped to 4.62 percent, the lowest point since June 2003. That rate was 4.83 percent last week, Freddie Mac said.

Average rates on five-year, adjustable-rate mortgages fell to 5.49 percent, compared with 5.57 percent last week. Rates on one-year, adjustable-rate mortgages rose to 4.95 percent, up from 4.85 percent last week.

The rates do not include add-on fees known as points. The nationwide fee for 30-year mortgages averaged 0.6 point for this week. Fees for 15-year mortgages and five-year adjustable rate mortgages averaged 0.7 point, compared with 0.5 point for one-year adjustable-rate mortgages.

Freddie Mac, and sibling company Fannie Mae, own or guarantee about half of the $11.5 trillion in U.S. outstanding home loan debt. The government seized control of the companies in September.