Sales of previously owned U.S. homes unexpectedly rose in October to the highest level in almost 15 years, extending a housing market boom fueled by record-low mortgage rates and buyers’ desire for properties in the suburbs.

Contract closings increased 4.3% from the prior month to an annualized 6.85 million, the strongest pace since November 2005, according to National Association of Realtors data released Thursday. The October rate exceeded all economists’ forecasts in a Bloomberg survey, which had a median estimate of 6.47 million.