Long-term U.S. mortgage rates edged up slightly this week, reaching their highest levels since late June.

Mortgage buyer Freddie Mac said Thursday the average rate on 30-year, fixed-rate mortgages rose to 4.54 percent from 4.52 percent last week. Long-term loan rates have been running at their highest levels in seven years. The average benchmark 30-year rate reached a high this year of 4.66 percent on May 24. The rate stood at 3.92 percent a year ago.

The average rate on 15-year, fixed-rate loans ticked up to 4.02 percent this week from 4.00 percent last week.

Home sales haven't marked strong gains this summer despite the healthy economy and job market. Steadily rising home prices combined with higher mortgage rates "appear to be giving more prospective buyers pause," said Freddie Mac's chief economist Sam Khater.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country between Monday and Wednesday each week.

The average doesn't include extra fees, known as points, which most borrowers must pay to get the lowest rates.

The average fee on 30-year fixed-rate mortgages rose to 0.5 point from 0.4 point last week. The fee on 15-year mortgages was unchanged at 0.4 point.

The average rate for five-year adjustable-rate mortgages held steady from last week at 3.87 percent. The fee increased to 0.4 point from 0.3 point.