The 30-year, fixed-rate mortgage increased slightly during the week ending Sept. 16, up 2 basis points to 4.37% with an average origination point 0.7, according to the Freddie Mac Primary Mortgage Market Survey. The rate was 4.35% last week and 5.04% one year ago. The Bankrate survey of large banks and thrifts reported the average rate for a 30-year FRM decreased to near-record lows at 4.54% with a 0.37 origination point, up from 4.58% last week. The record low set in the nearly 25-year-old survey is 4.53%, achieved two weeks ago. Rates for 15-year FRMs are also plunging, setting a historic record low for Freddie Mac. The GSE said the average rate for a 15-year FRM averaged 3.82% with an average 0.6 origination point, down from last week's average of 3.83% and a year ago, when the average was 4.47%. The average is a new low for the 15-year survey which began in 1991. Bankrate also put the average rate for a 15-year FRM at a new record low at 4%, down from 4.06%. Vice president and chief economist at Freddie Mac, Frank Nothaft, said that low rates (the 30-year FRM has been below 5% for 19 weeks) are motivating people to refinance their home more than buy new homes. "Currently, four out of five mortgage applications are for refinancing existing mortgage debt, based on figures by the Mortgage Bankers Association," Nothaft said. "Homeowners reduced their financial obligations relative to disposable personal income during the second quarter of 2010 to the lowest share in almost eight years, according to the Federal Reserve." Rates for 5-year adjustable rate mortgages (ARM) decreased. The GSE said the rate was down to 3.55% with an average origination point of 0.6 from 3.56%. The rate for a 5-year ARM was 4.51% one year ago. Bankrate posted the rate for 5-year ARMs declared a new record low, 3.78%, from 3.91% last week. The one-year Treasury-indexed ARM averaged 3.4% with an average 0.7 point this week, down from last week when it averaged 3.46%. At this time last year, the one-year ARM averaged 4.58%. Write to Christine Ricciardi.