U.S. fixed mortgage rates this week edged down slightly near or at record lows, as home construction built up steam, the Primary Mortgage Market Survey released Thursday by Freddie Mac showed. The mortgage giant said the 30-year fixed-rate mortgage (FRM) was 3.37 percent in the week ending Oct. 18, down from last week\'s 3.39 percent, very near to its record low of 3.36 percent. It has been below 4 percent all but one week in 2012. The 15-year FRM, a popular choice for those looking to refinance, went down to 2.66 percent from 2.70 percent in the previous week, hitting a new all-time low. It has been below 3 percent since the last week in May. Meanwhile, the 5-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) inched up to 2.75 percent, while the 1-year Treasury-indexed ARM was up to 2.60 percent. Before locking in the low rates, borrowers have to pay banking service fees, also known as points, which are calculated as a percentage of the loan, typically between 0.4 to 0.7. The U.S. Federal Reserve last month announced a new bond purchase plan of purchasing agency mortgage-backed securities (MBS) at a pace of 40 billion U.S. dollars per month, which directly dragged down the fixed mortgage rates. Lower rates have been an important incentive to house refinancing and buying since last fall. The housing market had been picking up steam as the economy continues to expand modestly in recent months, the Fed reported Wednesday. However, many economists say the market still needs years to recover entirely as the bottom will be prolonged.