WASHINGTON » Average U.S. rates on fixed mortgages rose this week but remained near record lows, keeping home buying more affordable.

Mortgage buyer Freddie Mac says the average rate on the 30-year fixed loan increased to 3.42 percent from 3.38 percent last week. That’s still near the 3.31 percent rate reached in November, the lowest in records dating to 1971.

The average on the 15-year fixed mortgage increased to 2.71 percent from 2.66 percent last week. The record low is 2.63 percent.

The rate on the 30-year fixed mortgage averaged 3.66 percent in 2012, the lowest annual average in 65 years.

More affordable mortgages are a key reason the housing market began to come back last year. Many economists predict the housing recovery will strengthen in 2013.