Fixed mortgage rates on long-term loans in the United States rose off of record lows in the week ending Thursday, the Federal Home Loan Mortgage Corp. said. The average 30-year fixed mortgage, which has been below 4 percent for every week but one in 2012, rose from 3.49 percent to 3.55 percent with an average 0.7 points, Freddie Mac said. A year earlier, interest rates for 30-year, fixed-rate loans were at 4.39 percent. For 15-year loans in the week ending Thursday, interest rates rose from 2.8 percent to 2.83 percent with an average 0.6 points. A year ago, 15-year loan rates averaged 3.54 percent. Interest rates for five-year adjustable-rate mortgages rose from 2.74 percent to 2.75 percent in the week with 0.6 points. In the same week of 2011, rates for five-year ARM contracts stood at 3.18 percent. The average interest rates for one-year ARM contracts dropped from 2.71 percent to 2.7 percent in the week with 0.4 points. Rates a year ago for one-year ARM contracts averaged 3.02 percent.