Acquisitions and dispositions of portfolios of real estate assets present certain challenges and complexities that are not present in a transaction involving a single asset.  For example, will the deal be an "all-or-nothing" transaction such that the buyer has to close on all assets and cannot decline to close on assets plagued by serious defects without terminating the entire transaction?  Will all assets in the portfolio close at the same time, or will the closings be held in phases over time?  Any approach to addressing these questions creates additional issues, and there are a number of factors to consider in negotiating the sale of a real estate portfolio.