Sales of New York City apartment buildings tumbled to near-decade lows last year, after new rent rules scared investors away from properties with regulated units.

By every measure, it was a terrible 2019 for those in the business of owning and selling multifamily properties. The dollar value of purchases across all boroughs fell 40% from the prior year to $6.91 billion, the lowest total since 2011, according to a report by brokerage Ariel Property Advisors. There were 290 multifamily deals -- a 36% decline, and the first year with fewer than 300 transactions in records dating to 2010.