The 522-unit Archstone Warner Center has been sold to Chicago real estate development trust AMLI Residential Properties Inc. in a deal valued at $100 million. The apartment complex was just one just a few dozen still held by the multifamily property developer, owned by the estate of bankrupt New York investment bank Lehman Bros. The estate previously sold off the vast portion of Archstone’s portfolio in November to a joint venture of Avalon Bay Communities Inc. of Washington D.C. and Chicago’s Equity Residential for $6.5 billion in cash and stock. The 21200 Kittridge St. property, which was built in 2006, sold for the relatively low price of $191,571 a unit, according to CoStar Group Inc. By comparison, Archstone sold a 1970s-era 191-unit property in Thousand Oaks for $269,000 per unit in August as Lehman was preparing to take Archstone public. However, the Lehman estate decided against pursuing the initial public offering and instead sold the unit off to the joint venture. AMLI is a privately held REIT that focuses on multi-family developments. It has properties in nine states, including the AMLI on the Boulevard in Studio City.