WASHINGTON (Reuters) - Contracts to buy U.S. previously owned homes unexpectedly fell in September likely as some potential buyers delayed purchases amid higher prices. The National Association of Realtors (NAR) said on Thursday its Pending Home Sales Index, based on signed contracts, decreased 2.3% last month to 116.7. Pending home sales fell in all four regions. Economists polled by Reuters had forecast contracts, which become sales after a month or two, would be unchanged. Pending home sales dropped 8.0% in September on a year-on-year basis. Scarce inventory has led to double-digit growth in home prices. “Some potential buyers have momentarily paused their home search with intentions to resume in 2022,” said Lawrence Yun, NAR’s chief economist. Demand for housing surged early in the coronavirus pandemic amid an exodus from cities to suburbs and other lower-density locations as Americans sought more spacious accommodations for home offices and online schooling. The buying frenzy has abated as workers return to offices and schools reopened for in-person learning, thanks to COVID-19 vaccinations. The high cost of homes is squeezing first-time buyers out of the market. The NAR reported last week that the share of first-time buyers in September was the smallest since July 2015. Reporting by Lucia Mutikani; Editing by Paul Simao