U.S. mortgage rate fell to the lowest level for the tenth time in 11 weeks as yields on government debt dropped and investors concerned about the economy.

Freddie Mac (OTCBB: FMCC), a government sponsored enterprise (GSE) of the United States federal government, said Thursday that interest rates on U.S. 30-year fixed mortgage, the most widely used loan, was 4.32 percent the week ended September 2, down 0.04 percent compared to the last week. 4.32 percent is the lowest since The Federal Home Loan Mortgage Corporation (FHLMC) started tracking rates in 1971.

In term of the average on 15-year fixed loan, the rate was down 0.05 percent from the last week. There have been decline in rates since springs as investors have moved to Treasury bonds for the shake of safety, which has lowered their yields. Mortgage rates haves a connection with yields on Treasuries on mortgage-backed securities.

15-year mortgages averaged 4.54 percent, the one-year ARM 4.62, and the 5/1 ARM 4.59 percent a year earlier.

Amy Crews Cutts, Freddie Mac deputy chief economist, said in a statement that the price growth of core personal expenditures in one year kept unchanged at 1.4 percent in July.

Federal Reserve Chairman Ben Bernanke also said that inflation should remain near current readings for some time before rising slowly amid growing economy and reasonably stable inflation expectations.

Refinancing is at its highest level since May 2009. However, a wave of refinancing from borrowers appeared due to the low rates, with almost 83 percent of all new loans.

Mortgage applications increased 2.7 percent last week as investors have been seeking lower rates. Nevertheless, the rock-bottom rates could not lift the slumping real estate market up, offering a glimmer of hope for the market. It has failed to find footing in the aftermath of the expiration of popular home buyer tax credits.

It is over a decade since home sales have been at its lowest level, tumbling in recent months while home prices are forecast to trek downward again due to increasing supply of homes and mounting foreclosures. Potential home buyers are reluctant to purchases amid fragile economic growth and high unemployment rate. They may be waiting for even lower home prices.

Certainly, home sales are greatly impacted by the lowest mortgage rates in decades. However, home purchase demand remains muted, according to Diane Saatchi, senior vice president at Saunders & Associates in Bridgehampton, New York.

The second-largest U.S. mortgage finance company got mortgage rates together from lenders countrywide from Monday to Wednesday of each week to calculate the national average. There is a dramatic fluctuation in the rates even within a given day.