Long-term U.S. mortgage rates edged higher this week, marking a fourth straight week of increases though rates remain at historically low levels.

Mortgage giant Freddie Mac says the average for the benchmark 30-year fixed-rate mortgage ticked up to 3.45 percent from 3.43 percent last week. The average rate is down sharply from 3.94 percent a year ago, and remains close to its all-time low of 3.31 percent in November 2012.

The 15-year fixed mortgage rate rose to 2.76 percent from 2.74 percent last week.

Record-low interest rates this year have helped spur home purchases and boost the housing market.

(AP)