WASHINGTON (AP) — Average long-term U.S. mortgage rates were slightly lower to unchanged this week amid expectations that the Federal Reserve isn't ready yet to raise its key short-term interest rate.

Mortgage giant Freddie Mac said Thursday the average rate on a 30-year fixed-rate mortgage slipped to 3.76 percent from 3.79 percent a week earlier. The rate on 15-year fixed-rate mortgages stayed at 2.98 percent.

It was the 14th straight week of rates below 4 percent, and they are well below last year's levels. A year ago, the average 30-year mortgage rate was 3.98 percent, while the rate for 15-year loans was 3.13 percent.

The Fed announced Wednesday that it's keeping the key rate at a record low near zero in light of a weak global economy, slower U.S. hiring and subpar inflation. But it signaled the possibility of a rate hike in December.

It was the first time in seven years of record-low rates that the Fed has explicitly raised the possibility that it could raise the benchmark rate at its next meeting.

Data issued Thursday showed that September marked a slowdown in Americans signing contracts to buy homes, the second consecutive decline for a real estate market that has been rebounding for the first half of 2015.

The National Association of Realtors said its seasonally-adjusted index of pending home sales dropped 2.3 percent to 106.8 last month. The index has risen 3 percent over the past 12 months, aided by solid hiring levels and low mortgage rates that fueled stronger demand during the traditional summer buying season.

Sales of new homes plunged sharply in September to the slowest pace in 10 months, as higher prices and slower economic growth weigh on the housing market, according to government data out Monday.

To calculate average mortgage rates, Freddie Mac surveys lenders across the country at the beginning of 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 held steady from last week at 0.6 point. The fee for a 15-year loan rose to 0.6 point from 0.5 point.

The average rate on five-year adjustable-rate mortgages was unchanged at 2.89 percent; the fee remained at 0.4 point. The average rate on one-year ARMs fell to 2.54 percent from 2.62 percent; the fee held at 0.2 point.