StreetEasy, founded in 2006, offers sales and rental listings through partnerships with New York real estate firms. It also provides information about condominiums, co-ops, new developments and luxury real estate.
"StreetEasy is an incredibly strong and recognized brand in New York City, and complements Zillow's dominant and growing national brand," Zillow CEO Spencer Rascoff said in a statement.
The buyout is expected to close in the next few weeks.
Zillow also announced Monday a public offering of 2.5 million shares. Certain shareholders are offering an additional 2.5 million shares. The company won't receive any proceeds from the the selling stockholders.
Zillow Inc. (Z) plans to give the underwriters a 30-day option to buy up to an additional 753,522 shares.
Earlier this month Zillow reported second-quarter adjusted earnings and revenue that topped analyst expectations.