Aviv REIT, which specializes in owning and acquiring skilled nursing facilities, officially withdrew its plans for an initial public offering on Monday, about a month after it had decided to postpone the deal. The Chicago, IL-based company had originally scheduled to make its debut on Nov. 6 but ultimately shelved the $299 million IPO due to valuation pressures from potential investors. Aviv REIT was founded in 2005 and booked $86 million in sales for the 12 months ended June 30, 2009. Morgan Stanley, BofA Merrill Lynch, and Citi were set to be the lead underwriters on the deal.