[ by Melanie Gretchen ] Bank of America lightened up its balance sheet with the sale of a 31-story office tower in downtown Manhattan.  Following the sale to Beacon Capital Partners LLC and L&L Holding Co., the Charlotte, NC-based bank will continue to occupy the building with a lease for some 590,000 sf. What Bank of America Stands to Gain. While a spokesperson declined to give numbers, the WSJournal reported the sale at $230 million, or about $300 a square foot, according to the agreement made earlier this week.  If the sale was not based on the office market conditions in lower New York, then the transaction might raise questions about the bank's need for capital. And yet, in the context of the housing market, Bank of America has done well: as expectations that the World Trade Center, when completed, will drive down prices, buildings in lower Manhattan sold for an average of $249 a square foot in the 12 months through March, said Ben Thypin, director of market analysis for Real Capital Analytics Inc. Okay, nice job and good timing, BofA. [Bloomberg, 4/16/12].