Tishman Speyer Properties and Lehman Brothers Holdings Incorporated announced Tuesday that they will buy public real estate firm Archstone-Smith Trust in a deal worth at least $13.5 billion. Colorado based Archstone-Smith has a market capitalization of $12.3 billion, and it owns 86,000 apartments in several metropolitan areas around the United States, including New York City, Los Angeles, and Washington D.C. “Archstone is an exceptional company that has built one of the finest collections of multifamily assets in the industry,” said Tishman Speyer Senior Managing Director Rob Speyer. Tishman Speyer is a leading owner and operator of real estate in the world. It owns several iconic properties around the world including New York City's Chrysler Building, London's City Point, and Berlin's Sony Center. Archstone's board unanimously approved the bid, priced at $60.75 per share, and shareholders must now vote on the buyout, but no date has yet been announced. Archstone said the deal was worth $22.2 billion, including debt to be assumed and refinanced. The deal is one of the largest conversions of a publicly traded real estate trust to privet ownership. Shares of Archstone-Smith rose $5.47, nearly 10 percent, to $60.70 Tuesday, after news of the now pending acquisition emerged.