WASHINGTON (AP) — Americans signed fewer contracts to purchase homes in October, as would-be buyers struggled to find available properties.

The National Association of Realtors says its pending home sales index, which measures the number of purchase contracts signed, fell 1.7% last month. The signed contracts become final purchases 1-2 months later.

Still, declining mortgage rates over time have lifted home sales. The index is up 4.4% from a year ago.

Mortgage rates have fallen sharply in the past year, partly because the Federal Reserve has lowered its benchmark short-term interest rate. That has partially offset steady increases in average home prices across the nation.

But Americans who want to buy a home have few choices. The number of available houses fell to 1.8 million in October, a record low for that month.