U.S. fixed mortgage rates this week decreased once again to new all-time record lows, said the Primary Mortgage Market Survey released Thursday by Freddie Mac.

The mortgage giant said that 30-year fixed-rate mortgage (FRM) was 3.89 percent for the week ending January 12, 2012, the lowest rate ever, down from last week's 3.91 percent. Last year at this time, the 30-year FRM averaged 4.71 percent.

The 15-year FRM averaged 3.16 percent, down from its previous week average of 3.23 percent. A year ago at this time, the 15-year FRM averaged 4.08 percent.

The 5-year Treasury-indexed hybrid adjustable-rate mortgage ( ARM) averaged 2.82 percent, down from last week when it averaged 2. 86 percent, but the 1-year Treasury-indexed ARM averaged 2.76 percent this week, up from last week when it averaged 2.80 percent.

Low rates offer a great opportunity for those who can afford to buy or refinance. Still, few people are able to take advantage of them.

Mortgage rates were lower because they followed the yield on the 10-year U.S. Treasury note, which fell below 2 percent. They could fall even lower this year if the Fed launches another round of bond purchases, as some economists expect.

Frank Nothaft, Freddie Mac's chief economist, said that a weak job market would continue to keep the impact of lower mortgage rates subtle.

To calculate average mortgage rates, Freddie Mac collects rates from lenders across the country on Monday through Wednesday of each week.

Freddie Mac was established by Congress in 1970 to provide liquidity, stability and affordability to the nation's residential mortgage markets.