WASHINGTON (AP) — Average U.S. mortgage rates fell for the third straight week, making it more affordable to borrow to buy a home.

Mortgage company Freddie Mac said Thursday that the nationwide average for a 30-year loan fell to 4.12 percent from 4.19 percent last week. The average for a 15-year mortgage, a popular choice for people who are refinancing, also declined to 3.3 percent from 3.36 percent.

The 30-year rate is down from 4.53 percent at the start of the year.

Rates have fallen even though the Federal Reserve appears set at the end of this month to end its monthly bond purchases, which are intended to keep long-term borrowing rates low. Yet Fed officials have indicated that they will continue to hold shorter-term rates at near-zero levels until there are signs of rising inflation.

Fed actions often influence the yield on the 10-year Treasury note, which affects mortgage rates. The 10-year note was trading at 2.32 percent at midday Thursday, down sharply from 2.41 percent a week earlier.

Mortgage rates are falling as the housing market has cooled off. Average price growth has slowed, rising just 6.4 percent in August compared with a year ago, according to real estate data provider CoreLogic. That's down from annual average gains of as much as 12 percent toward the end of last year.

Similarly, sales of existing homes also declined in August. Fewer investors bought properties, and first-time buyers have yet to return to the market, according to the National Association of Realtors.

Sales of new homes shot up in August, yet it remains below historic averages, according to Commerce Department data.

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. One point equals 1 percent of the loan amount.

The average fee for a 30-year mortgage rose to 0.5 point from 0.4 point last week. The fee for a 15-year mortgage remained at 0.5 point.

The average rate on a five-year adjustable-rate mortgage fell to 3.05 percent from 3.06 percent. The fee stayed at 0.5 point.

For a one-year ARM, the average rate was unchanged at 2.42 percent. The fee held at 0.4 point.