WASHINGTON (AP) — The average U.S. rate on a 15-year fixed mortgage rose above 3 percent this week for the first time in a year, while the rate on the 30-year fixed loan approached 4 percent.

Mortgage buyer Freddie Mac said Thursday that the rate on the 30-year loan jumped to 3.91 percent from 3.81 percent last week. That's the highest since March 2012.

The rate on the 15-year loan rose to 3.03 percent from 2.98 percent. That's the highest since last May.

Concerns that the Federal Reserve may scale back its bond purchases have pushed rates higher over the last month. Still, mortgage rates remain low by historical standards. The 30-year loan hit a record 3.31 percent rate in November. The 15-year loan fell to its low of 2.56 percent a month ago.

Mortgage rates are rising because they tend to follow the yield on the 10-year Treasury note. The yield on the 10-year note climbed as high as 2.2 percent last week, its highest level in more than two years. It has since slipped to 2.1 percent in early trading Thursday. That compares with 1.63 percent at the beginning of May.

The Fed's $85-billion-a-month in Treasury and mortgage bond purchases have pushed down long-term interest rates. As speculation has grown that the Fed will slow those purchases, investors have driven rates up. That has decreased the value of bonds with lower yields.

The rise in mortgage rates has slowed mortgages applications. They dropped 11.5 percent in the week ended May 31 from the previous week, the Mortgage Bankers Association said Wednesday.

Still, cheaper mortgages have helped boost home sales and prices this year, strengthening a housing recovery that began in 2012.

Both home prices and sales increased throughout the country from April through late May, according to a Fed survey released Wednesday, and several regional districts noted that sellers were receiving multiple offers.

Data provider CoreLogic said Tuesday that home prices soared 12.1 percent in April from a year earlier, the biggest gain since February 2006.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country on Monday through Wednesday each week. The average doesn't include extra fees, known as points, which most borrowers must pay to get the lowest rates. One point equals 1 percent of the loan amount.

The average fee for 30-year mortgages dipped to 0.7 point from 0.8 point last week. The fee for 15-year loans was unchanged at 0.7 point.

The average rate on a one-year adjustable-rate mortgage rose to 2.58 percent from 2.54 percent. The fee for one-year adjustable-rate loans declined to 0.4 point from 0.5.

The average rate on a five-year adjustable-rate mortgage jumped to 2.74 percent from 2.66 percent. The fee held steady at 0.5.